Add Legacy-style Book Binder

BUILDING.txt

@@ -0,0 +1,125 @@
+Rivencraft Build Instructions
+============================
+
+These instructions apply when source code, models, textures, data, or other
+resources have been changed.
+
+Requirements
+------------
+
+- Java 21 JDK
+- A working Gradle wrapper
+- The project dependencies available in the Gradle cache, or network access
+  for Gradle to download them
+
+The project targets Minecraft 1.21.1 and NeoForge 21.1.251.
+
+1. Open the project directory
+--------------------------------
+
+    cd /path/to/rivencraft
+
+2. Check the changed files
+--------------------------
+
+Confirm that model, texture, and other resource files are inside
+`src/main/resources`. Java source files belong under `src/main/java`.
+
+For example, block models are normally stored under:
+
+    src/main/resources/assets/rivencraft/models/block/
+
+Resource files placed under `src/main/resources` are automatically included in
+the finished mod JAR by Gradle.
+
+3. Update the version when appropriate
+---------------------------------------
+
+Rivencraft uses the version format `x.y.z.b`:
+
+- `x`: major release
+- `y`: milestone completion
+- `z`: release slice
+- `b`: bug fixes and additional work within that slice
+
+Edit `mod_version` in `gradle.properties` before creating a new release. Do
+not reuse a version that has already been published.
+
+4. Build the mod
+----------------
+
+From the project directory, run:
+
+    ./gradlew build --offline
+
+If the required dependencies are not cached locally, remove `--offline`:
+
+    ./gradlew build
+
+On systems using mise-managed Java and Gradle, use:
+
+    mise exec -- ./gradlew build --offline
+
+5. Run the automated tests
+--------------------------
+
+To build and run the GameTest suite:
+
+    ./gradlew build runGameTestServer --offline
+
+Or, with mise:
+
+    mise exec -- ./gradlew build runGameTestServer --offline
+
+All required GameTests should pass before distributing a build.
+
+GameTests use `build/gametest-run/world`, separate from the normal development
+world. Before each run, Gradle removes that test world if it exceeds 512 MiB.
+Override the limit with `-PgameTestMaxWorldMiB=NUMBER`. A caller-supplied
+`-PgameTestRunDir` is never removed automatically.
+
+To run the suite in a fresh temporary directory instead, use:
+
+    test_dir=$(mktemp -d /tmp/rivencraft-gametest.XXXXXX)
+    ./gradlew runGameTestServer --offline -PgameTestRunDir="$test_dir"
+
+With mise, prefix the second command with `mise exec --`.
+
+6. Locate and inspect the JAR
+-----------------------------
+
+Build outputs are written to:
+
+    build/libs/
+
+The filename uses the configured version, for example:
+
+    build/libs/rivencraft-0.3.6.9.jar
+
+To verify that changed resource files are packaged:
+
+    unzip -l build/libs/rivencraft-VERSION.jar | rg 'models|textures|data'
+
+Replace `VERSION` with the actual version number.
+
+To create a checksum for distribution:
+
+    sha256sum build/libs/rivencraft-VERSION.jar
+
+7. Stop the Gradle daemon when finished
+----------------------------------------
+
+This is optional, but useful after a long test run:
+
+    ./gradlew --stop
+
+Release checklist
+-----------------
+
+- Confirm the version was incremented when required.
+- Confirm the build completed successfully.
+- Confirm all required GameTests passed.
+- Confirm changed resources are present in the JAR.
+- Generate and record the SHA-256 checksum.
+- Test the JAR in the target Minecraft 1.21.1 NeoForge instance.
+- Publish the JAR only after client-side testing is complete.

README.md

@@ -25,20 +25,56 @@ It occupies two adjacent blocks, with one shared inventory; loaded paper and
 the selected page appear on its Legacy-inspired model.
 Desks placed before 0.3.6.1 keep their old one-block footprint until broken
 and placed again; leave an adjacent space when replacing one.
-Its four collection tabs, paper input, ink vial input, empty glass-bottle return,
+Its 88 collection tabs, paper input, ink vial input, empty glass-bottle return,
 16-unit ink meter, and inventory persist
 through world saves; breaking it drops stored contents. The desk screen is a
-functional foundation styled after Legacy's left tabs, central writing surface,
+functional foundation using Legacy's original desk and scrollbar textures.
-and right inventory. Put vanilla paper in the
+Four tabs are visible at once; the controls above and below them move by four
+(1–4, 5–8, through 85–88). Each viewer can browse a different group. Existing
+four-tab desks retain their collections and supplies when upgraded.
+With a notebook selected, pick up a Page from your inventory and click an empty
+position on the left surface to store one page there. Clear search/filter/sort
+and turn off `ALL` to place pages at specific positions; occupied positions are
+never overwritten. A notebook tab exposes all 27 notebook positions (scroll to
+reach the rest); a loose-page tab exposes only its one occupied position.
+Empty tabs have no page storage until a notebook or page is put in the tab slot.
+Click a page on the desk surface to select it for copying. Drag a page from one
+notebook position to an empty position to move it, or onto another page to swap
+their positions. This also works between notebooks shown in the `ALL` view.
+Drag a page out of the panel to turn it back into an item. Drop it over a player
+inventory slot or desk tab to place it there; a tab with a notebook adds it to
+the first open position. Dropping elsewhere leaves the page on the cursor for
+normal inventory placement. The source notebook or tab loses the page only after
+a valid drop.
+Put vanilla paper in the
 upper-left slot and Ink Vials in the upper-right; a copy appears in the
 lower-left result slot when the selected page is valid. Taking it consumes one
-paper and, by default, one ink. An empty meter consumes a vial to refill and
+paper and, by default, one ink. An available vial refills an empty ink meter
-returns a vanilla glass bottle to the lower-right slot. The ALL browser searches
+when inserted or when copying uses its last ink, and returns a vanilla glass
-and filters symbols held in the desk's loose pages and Notebooks; selection
+bottle to the lower-right slot. Removing a bottle also retries a blocked refill.
-is validated against the server's current symbol catalog.
+Refilling waits if that slot is full or contains another item. The `AZ` control sorts
+visible pages by name; `ALL` shows pages held across every desk tab. Search and
+category filtering narrow the view without granting new pages, and cross-tab
+copy selection is checked by the server.
 Selecting a stored page on the desk surface shows its Legacy-proportioned
 portrait preview and name above the player inventory.
 
+## Book Binder
+
+Craft a Book Binder from three iron ingots and five planks. Put leather or an
+empty Notebook in the left cover slot. Enter a title, then place a Link Panel
+Page first in the horizontal page strip. Click a page in the strip with a
+written Page on the cursor to insert it before that position; click it with an
+empty cursor to take it out. The arrows or mouse wheel scroll through up to
+27 written Pages. Clicking the strip with a filled Notebook imports its Pages
+at that position and leaves the emptied Notebook on the cursor. The right slot
+outputs a Descriptive Book once the title, cover, and Link Panel are present.
+Inputs are consumed only when the result is taken.
+
+The completed book receives its Age identity when assembled. With only a Link
+Panel, it describes a randomly generated Age. Its writing is stored on the
+book; Milestone 5 will interpret additional symbols during Age generation.
+
 ## Linking Book
 
 Craft a Linking Book from a vanilla book and an ender pearl, then use it in the

build.gradle

@@ -78,6 +78,9 @@ neoForge {
         // The gametest system is also enabled by default for other run configs under the /test command.
         gameTestServer {
             type = "gameTestServer"
+            // Keep generated test Ages separate from worlds used by the dev client/server.
+            gameDirectory = project.file(project.findProperty('gameTestRunDir')
+                    ?: layout.buildDirectory.dir('gametest-run').get().asFile)
             systemProperty 'neoforge.enabledGameTestNamespaces', project.mod_id
         }
 
@@ -116,6 +119,44 @@ neoForge {
     }
 }
 
+// GameTests generate Ages, so their dedicated world can grow quickly across runs.
+// Never auto-delete a caller-supplied gameTestRunDir or a normal dev world.
+long gameTestWorldLimitMiB = providers.gradleProperty('gameTestMaxWorldMiB').orElse('512').get().toLong()
+if (gameTestWorldLimitMiB <= 0) {
+    throw new GradleException('gameTestMaxWorldMiB must be a positive number')
+}
+boolean customGameTestRunDir = providers.gradleProperty('gameTestRunDir').isPresent()
+File dedicatedGameTestDir = layout.buildDirectory.dir('gametest-run').get().asFile.canonicalFile
+File dedicatedGameTestWorld = new File(dedicatedGameTestDir, 'world')
+def cleanOversizedGameTestWorld = tasks.register('cleanOversizedGameTestWorld') {
+    doLast {
+        if (customGameTestRunDir) {
+            getLogger().lifecycle('Skipping automatic GameTest world cleanup for custom gameTestRunDir')
+            return
+        }
+
+        def worldDir = dedicatedGameTestWorld
+        if (!worldDir.isDirectory() || java.nio.file.Files.isSymbolicLink(worldDir.toPath())) {
+            return
+        }
+
+        def paths = java.nio.file.Files.walk(worldDir.toPath()).withCloseable { it.toList() }
+        long bytes = paths.sum(0L) { path ->
+            java.nio.file.Files.isRegularFile(path, java.nio.file.LinkOption.NOFOLLOW_LINKS)
+                    ? java.nio.file.Files.size(path) : 0L
+        }
+        long limit = gameTestWorldLimitMiB * 1024L * 1024L
+        if (bytes > limit) {
+            getLogger().lifecycle('Removing oversized GameTest world {} ({} MiB; limit {} MiB)',
+                    worldDir, Math.ceil(bytes / 1048576d) as long, gameTestWorldLimitMiB)
+            paths.toSorted(java.util.Comparator.reverseOrder()).each { java.nio.file.Files.delete(it) }
+        }
+    }
+}
+tasks.named('runGameTestServer').configure {
+    dependsOn(cleanOversizedGameTestWorld)
+}
+
 // Sets up a dependency configuration called 'localRuntime'.
 // This configuration should be used instead of 'runtimeOnly' to declare
 // a dependency that will be present for runtime testing but that is

docs/ASSET_PROVENANCE.md

@@ -10,8 +10,11 @@ project's GNU LGPL v3 license. Rivencraft itself uses the same license.
 | `assets/rivencraft/textures/gui/notebook_pages.png` | `assets/mystcraft/gui/bookui_pagel.png` | `9bc8ddc061845df0cd5ea47f4fdef773cff786ae` | Namespace/path rename only; Notebook draws the native 30×40 page at atlas coordinates `(156, 0)` |
 | `assets/rivencraft/textures/item/writing_desk.png` | `assets/mystcraft/textures/items/writingdesk.png` | `9bc8ddc061845df0cd5ea47f4fdef773cff786ae` | Namespace/path rename only |
 | `assets/rivencraft/textures/block/writing_desk.png` | `assets/mystcraft/textures/entity/desk.png` | `9bc8ddc061845df0cd5ea47f4fdef773cff786ae` | Namespace/path rename only |
-| `assets/rivencraft/textures/block/writing_desk_wood.png` and `writing_desk_inlay.png` | `assets/mystcraft/textures/entity/desk.png` | `9bc8ddc061845df0cd5ea47f4fdef773cff786ae` | Cropped opaque wood and red inlay regions for the two-block model |
+| `assets/rivencraft/textures/gui/writing_desk_legacy.png` | `assets/mystcraft/gui/writingdesk.png` | `9bc8ddc061845df0cd5ea47f4fdef773cff786ae` | Namespace/path rename only; full desk panel, tabs, and cycling controls at original atlas coordinates |
-| `assets/rivencraft/textures/gui/writing_desk_legacy.png` | `assets/mystcraft/gui/writingdesk.png` | `9bc8ddc061845df0cd5ea47f4fdef773cff786ae` | Namespace/path rename only; solid GUI backing sampled from Legacy atlas |
+| `assets/rivencraft/textures/gui/scrollbar.png` | `assets/mystcraft/gui/scrollbar.png` | `9bc8ddc061845df0cd5ea47f4fdef773cff786ae` | Namespace/path rename only; tiled track and normal/pressed thumb |
+| `assets/rivencraft/textures/block/book_binder.png` | `assets/mystcraft/textures/entity/bookbinder/bookbinder.png` | `9bc8ddc061845df0cd5ea47f4fdef773cff786ae` | Namespace/path rename only; Book Binder model uses this body texture |
+| `assets/rivencraft/textures/block/book_binder_press.png` | `assets/mystcraft/textures/entity/bookbinder/press_part.png` | `9bc8ddc061845df0cd5ea47f4fdef773cff786ae` | Namespace/path rename only; Book Binder model uses this press texture |
+| `assets/rivencraft/textures/gui/book_binder_legacy.png` | `assets/mystcraft/gui/pagebinder.png` | `9bc8ddc061845df0cd5ea47f4fdef773cff786ae` | Namespace/path rename only; Book Binder GUI uses the original 176×181 panel |
 | `assets/rivencraft/textures/item/linking_book_unwritten.png` | `assets/mystcraft/textures/items/unlinked.png` | `9bc8ddc061845df0cd5ea47f4fdef773cff786ae` | Namespace/path rename only |
 | `assets/rivencraft/textures/item/page_link_panel.png` | `page_background.png` and `PageBuilder.BasicPageSprite` | `9bc8ddc061845df0cd5ea47f4fdef773cff786ae` | Reproduces the legacy 160 px scale, black panel at `(25,30)`–`(135,75)`, and 128 px resample |
 | `assets/rivencraft/textures/item/page_symbol*.png` and `page_unresolved.png` | `page_background.png`, `textures/symbolcomponents.png`, `WordData`, `ModSymbols`, and `PageBuilder.PageSprite` | `9bc8ddc061845df0cd5ea47f4fdef773cff786ae` | Static 1.21.1 renditions of the legacy runtime-composed four-word symbol pages; `normal_time` uses the legacy Full Length poem |

gradle.properties

@@ -35,7 +35,7 @@ mod_name=Rivencraft
 # The license of the mod. Review your options at https://choosealicense.com/. All Rights Reserved is the default.
 mod_license=LGPL-3.0-or-later
 # The mod version. Rivencraft uses the x.y.z.b policy documented in README.md.
-mod_version=0.3.6.1
+mod_version=0.3.7.2
 immersive_portals_version=6.0.7
 # The group ID for the mod. It is only important when publishing as an artifact to a Maven repository.
 # This should match the base package used for the mod sources.

src/main/java/net/dnorberg/rivencraft/block/BookBinderBlock.java

@@ -0,0 +1,66 @@
+package net.dnorberg.rivencraft.block;
+
+import com.mojang.serialization.MapCodec;
+import net.dnorberg.rivencraft.block.entity.BookBinderBlockEntity;
+import net.dnorberg.rivencraft.menu.BookBinderMenu;
+import net.minecraft.core.BlockPos;
+import net.minecraft.core.Direction;
+import net.minecraft.network.chat.Component;
+import net.minecraft.server.level.ServerPlayer;
+import net.minecraft.world.Containers;
+import net.minecraft.world.InteractionResult;
+import net.minecraft.world.SimpleMenuProvider;
+import net.minecraft.world.entity.player.Player;
+import net.minecraft.world.item.context.BlockPlaceContext;
+import net.minecraft.world.level.Level;
+import net.minecraft.world.level.block.BaseEntityBlock;
+import net.minecraft.world.level.block.RenderShape;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.world.level.block.state.StateDefinition;
+import net.minecraft.world.level.block.state.properties.BlockStateProperties;
+import net.minecraft.world.level.block.state.properties.DirectionProperty;
+import net.minecraft.world.level.block.entity.BlockEntity;
+import net.minecraft.world.phys.BlockHitResult;
+
+public final class BookBinderBlock extends BaseEntityBlock {
+    public static final MapCodec<BookBinderBlock> CODEC = simpleCodec(BookBinderBlock::new);
+    public static final DirectionProperty FACING = BlockStateProperties.HORIZONTAL_FACING;
+
+    public BookBinderBlock(Properties properties) {
+        super(properties);
+        registerDefaultState(stateDefinition.any().setValue(FACING, Direction.NORTH));
+    }
+
+    @Override public MapCodec<? extends BaseEntityBlock> codec() { return CODEC; }
+    @Override protected void createBlockStateDefinition(StateDefinition.Builder<net.minecraft.world.level.block.Block, BlockState> builder) {
+        builder.add(FACING);
+    }
+    @Override public BlockState getStateForPlacement(BlockPlaceContext context) {
+        Direction facing = context.getHorizontalDirection().getOpposite();
+        return defaultBlockState().setValue(FACING, facing);
+    }
+    @Override protected RenderShape getRenderShape(BlockState state) { return RenderShape.MODEL; }
+    @Override public BlockEntity newBlockEntity(BlockPos pos, BlockState state) {
+        return new BookBinderBlockEntity(pos, state);
+    }
+    @Override protected InteractionResult useWithoutItem(BlockState state, Level level, BlockPos pos,
+                                                          Player player, BlockHitResult hit) {
+        if (!level.isClientSide && player instanceof ServerPlayer serverPlayer
+                && level.getBlockEntity(pos) instanceof BookBinderBlockEntity binder) {
+            serverPlayer.openMenu(new SimpleMenuProvider(
+                    (id, inventory, ignored) -> new BookBinderMenu(id, inventory, binder),
+                    Component.translatable("container.rivencraft.book_binder")),
+                    buffer -> buffer.writeBlockPos(pos));
+        }
+        return InteractionResult.sidedSuccess(level.isClientSide);
+    }
+    @Override protected void onRemove(BlockState state, Level level, BlockPos pos,
+                                      BlockState replacement, boolean moving) {
+        if (!state.is(replacement.getBlock()) && !level.isClientSide
+                && level.getBlockEntity(pos) instanceof BookBinderBlockEntity binder) {
+            Containers.dropContents(level, pos, binder);
+            level.updateNeighbourForOutputSignal(pos, this);
+        }
+        super.onRemove(state, level, pos, replacement, moving);
+    }
+}

src/main/java/net/dnorberg/rivencraft/block/entity/BookBinderBlockEntity.java

@@ -0,0 +1,258 @@
+package net.dnorberg.rivencraft.block.entity;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
+import net.dnorberg.rivencraft.book.AgeReference;
+import net.dnorberg.rivencraft.book.AgeRegistrySavedData;
+import net.dnorberg.rivencraft.item.PageItem;
+import net.dnorberg.rivencraft.registry.ModBlockEntities;
+import net.dnorberg.rivencraft.registry.ModDataComponents;
+import net.dnorberg.rivencraft.registry.ModItems;
+import net.dnorberg.rivencraft.writing.NotebookContents;
+import net.dnorberg.rivencraft.writing.OrderedWriting;
+import net.dnorberg.rivencraft.writing.PageContent;
+import net.dnorberg.rivencraft.writing.WritingEntry;
+import net.minecraft.core.BlockPos;
+import net.minecraft.core.HolderLookup;
+import net.minecraft.core.NonNullList;
+import net.minecraft.core.component.DataComponents;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.network.chat.Component;
+import net.minecraft.network.protocol.Packet;
+import net.minecraft.network.protocol.game.ClientGamePacketListener;
+import net.minecraft.network.protocol.game.ClientboundBlockEntityDataPacket;
+import net.minecraft.world.Container;
+import net.minecraft.world.ContainerHelper;
+import net.minecraft.world.entity.player.Player;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.Items;
+import net.minecraft.world.level.block.entity.BlockEntity;
+import net.minecraft.world.level.block.state.BlockState;
+import net.minecraft.server.level.ServerLevel;
+
+/** Persistent inputs for a binder; the assembled output is never stored here. */
+public final class BookBinderBlockEntity extends BlockEntity implements Container {
+    public static final int COVER = 0;
+    public static final int LINK_PANEL = 1;
+    public static final int NOTEBOOK = 2;
+    public static final int FIRST_PAGE = 3;
+    public static final int PAGE_COUNT = NotebookContents.MAX_PAGES;
+    public static final int SIZE = FIRST_PAGE + PAGE_COUNT;
+    public static final int MAX_TITLE_LENGTH = 32;
+
+    private NonNullList<ItemStack> items = NonNullList.withSize(SIZE, ItemStack.EMPTY);
+    private String title = "";
+    private UUID pendingAgeId;
+
+    public BookBinderBlockEntity(BlockPos pos, BlockState state) {
+        super(ModBlockEntities.BOOK_BINDER.get(), pos, state);
+    }
+
+    public String title() { return title; }
+
+    public void setTitle(String value) {
+        String normalized = value == null ? "" : value.strip();
+        if (normalized.length() > MAX_TITLE_LENGTH) normalized = normalized.substring(0, MAX_TITLE_LENGTH);
+        if (!normalized.equals(title)) {
+            title = normalized;
+            setChanged();
+        }
+    }
+
+    public static boolean validCover(ItemStack stack) {
+        return stack.is(Items.LEATHER) || stack.is(ModItems.NOTEBOOK.get())
+                && stack.getOrDefault(ModDataComponents.NOTEBOOK_CONTENTS.get(), NotebookContents.EMPTY).pageCount() == 0;
+    }
+
+    private static boolean validPage(ItemStack stack) {
+        return stack.is(ModItems.PAGE.get()) && PageItem.content(stack).kind() != PageContent.Kind.LINK_PANEL;
+    }
+
+    @Override public int getContainerSize() { return SIZE; }
+    @Override public boolean isEmpty() { return items.stream().allMatch(ItemStack::isEmpty); }
+    @Override public ItemStack getItem(int slot) { return items.get(slot); }
+    @Override public ItemStack removeItem(int slot, int amount) {
+        ItemStack removed = ContainerHelper.removeItem(items, slot, amount);
+        if (!removed.isEmpty()) setChanged();
+        return removed;
+    }
+    @Override public ItemStack removeItemNoUpdate(int slot) { return ContainerHelper.takeItem(items, slot); }
+    @Override public void setItem(int slot, ItemStack stack) {
+        items.set(slot, stack);
+        if (stack.getCount() > getMaxStackSize()) stack.setCount(getMaxStackSize());
+        setChanged();
+    }
+    @Override public boolean canPlaceItem(int slot, ItemStack stack) {
+        return switch (slot) {
+            case COVER -> validCover(stack);
+            case LINK_PANEL -> stack.is(ModItems.PAGE.get())
+                    && PageItem.content(stack).kind() == PageContent.Kind.LINK_PANEL;
+            case NOTEBOOK -> stack.is(ModItems.NOTEBOOK.get());
+            default -> slot >= FIRST_PAGE && slot < SIZE && validPage(stack);
+        };
+    }
+    @Override public boolean stillValid(Player player) {
+        return level != null && level.isLoaded(worldPosition) && level.getBlockEntity(worldPosition) == this
+                && player.distanceToSqr(worldPosition.getX() + 0.5, worldPosition.getY() + 0.5,
+                        worldPosition.getZ() + 0.5) <= 64.0;
+    }
+
+    /** All checks precede any mutation so a failed assembly leaves every input intact. */
+    public boolean canAssemble() {
+        if (title.isBlank() || !validCover(items.get(COVER))
+                || !canPlaceItem(LINK_PANEL, items.get(LINK_PANEL))
+                || items.get(LINK_PANEL).getCount() != 1) return false;
+        for (int slot = FIRST_PAGE; slot < SIZE; slot++) {
+            ItemStack page = items.get(slot);
+            if (!page.isEmpty() && (!validPage(page) || page.getCount() != 1
+                    || PageItem.content(page).kind() == PageContent.Kind.BLANK)) return false;
+        }
+        return true;
+    }
+
+    public ItemStack previewBook() {
+        if (!canAssemble()) return ItemStack.EMPTY;
+        if (pendingAgeId == null) {
+            pendingAgeId = UUID.randomUUID();
+            setChanged();
+        }
+        List<WritingEntry> entries = new ArrayList<>();
+        entries.add(WritingEntry.linkPanel());
+        for (int slot = FIRST_PAGE; slot < SIZE; slot++) {
+            ItemStack page = items.get(slot);
+            if (!page.isEmpty()) entries.add(WritingEntry.symbol(PageItem.content(page).symbol().orElseThrow()));
+        }
+        ItemStack book = new ItemStack(ModItems.DESCRIPTIVE_BOOK.get());
+        book.set(ModDataComponents.AGE_REFERENCE.get(), new AgeReference(pendingAgeId, title));
+        book.set(ModDataComponents.BOOK_WRITING.get(), new OrderedWriting(entries));
+        book.set(DataComponents.CUSTOM_NAME, Component.literal(title));
+        return book;
+    }
+
+    /** Called once, on the server, after the output can be delivered. */
+    public boolean consumeAssembly() {
+        if (!canAssemble()) return false;
+        if (pendingAgeId == null) pendingAgeId = UUID.randomUUID();
+        if (level instanceof ServerLevel serverLevel)
+            AgeRegistrySavedData.resolveOrCreate(serverLevel, new AgeReference(pendingAgeId, title));
+        items.get(COVER).shrink(1);
+        if (items.get(COVER).isEmpty()) items.set(COVER, ItemStack.EMPTY);
+        items.get(LINK_PANEL).shrink(1);
+        if (items.get(LINK_PANEL).isEmpty()) items.set(LINK_PANEL, ItemStack.EMPTY);
+        for (int slot = FIRST_PAGE; slot < SIZE; slot++) items.set(slot, ItemStack.EMPTY);
+        title = "";
+        pendingAgeId = null;
+        setChanged();
+        return true;
+    }
+
+    public int nextPageIndex() {
+        for (int index = PAGE_COUNT - 1; index >= 0; index--) {
+            if (!items.get(FIRST_PAGE + index).isEmpty()) return index + 1;
+        }
+        return 0;
+    }
+
+    /** Insert before a displayed page, shifting later pages as Legacy's strip does. */
+    public boolean insertPage(int index, ItemStack page) {
+        int end = nextPageIndex();
+        if (index < 0 || index > end || end >= PAGE_COUNT || page.getCount() != 1
+                || !validPage(page)) return false;
+        for (int current = end; current > index; current--)
+            items.set(FIRST_PAGE + current, items.get(FIRST_PAGE + current - 1));
+        items.set(FIRST_PAGE + index, page.copy());
+        setChanged();
+        return true;
+    }
+
+    /** Take a page back to the cursor, closing the gap in the displayed order. */
+    public ItemStack takePage(int index) {
+        int end = nextPageIndex();
+        if (index < 0 || index >= end || items.get(FIRST_PAGE + index).isEmpty()) return ItemStack.EMPTY;
+        ItemStack removed = items.get(FIRST_PAGE + index);
+        for (int current = index; current < end - 1; current++)
+            items.set(FIRST_PAGE + current, items.get(FIRST_PAGE + current + 1));
+        items.set(FIRST_PAGE + end - 1, ItemStack.EMPTY);
+        setChanged();
+        return removed;
+    }
+
+    /** Move every Notebook page as one transaction, leaving its empty cover in the input slot. */
+    public boolean importNotebook() {
+        ItemStack notebook = items.get(NOTEBOOK);
+        ItemStack emptied = importNotebookFromStack(notebook, nextPageIndex());
+        if (emptied.isEmpty()) return false;
+        items.set(NOTEBOOK, emptied);
+        setChanged();
+        return true;
+    }
+
+    /** Import a Notebook from either its stored slot or the player's cursor. */
+    public ItemStack importNotebookFromStack(ItemStack notebook, int index) {
+        if (!notebook.is(ModItems.NOTEBOOK.get()) || notebook.getCount() != 1) return ItemStack.EMPTY;
+        List<ItemStack> pages = notebook.getOrDefault(ModDataComponents.NOTEBOOK_CONTENTS.get(), NotebookContents.EMPTY).pages();
+        if (pages.isEmpty()) return ItemStack.EMPTY;
+        int end = nextPageIndex();
+        if (index < 0 || index > end) return ItemStack.EMPTY;
+        boolean link = false;
+        List<ItemStack> writing = new ArrayList<>();
+        for (ItemStack page : pages) {
+            if (page.isEmpty()) continue;
+            if (!page.is(ModItems.PAGE.get()) || page.getCount() != 1) return ItemStack.EMPTY;
+            if (PageItem.content(page).kind() == PageContent.Kind.LINK_PANEL) {
+                if (link || !items.get(LINK_PANEL).isEmpty()) return ItemStack.EMPTY;
+                link = true;
+            } else if (validPage(page)) writing.add(page);
+            else return ItemStack.EMPTY;
+        }
+        if (end + writing.size() > PAGE_COUNT || writing.isEmpty() && !link) return ItemStack.EMPTY;
+        if (link) {
+            for (ItemStack page : pages) {
+                if (!page.isEmpty() && PageItem.content(page).kind() == PageContent.Kind.LINK_PANEL) {
+                    items.set(LINK_PANEL, page.copy());
+                    break;
+                }
+            }
+        }
+        for (int current = end - 1; current >= index; current--)
+            items.set(FIRST_PAGE + current + writing.size(), items.get(FIRST_PAGE + current));
+        for (ItemStack page : writing) items.set(FIRST_PAGE + index++, page.copy());
+        ItemStack emptyNotebook = notebook.copy();
+        emptyNotebook.set(ModDataComponents.NOTEBOOK_CONTENTS.get(), NotebookContents.EMPTY);
+        setChanged();
+        return emptyNotebook;
+    }
+
+    @Override public void clearContent() {
+        items = NonNullList.withSize(SIZE, ItemStack.EMPTY);
+        title = "";
+        pendingAgeId = null;
+        setChanged();
+    }
+    @Override protected void loadAdditional(CompoundTag tag, HolderLookup.Provider registries) {
+        super.loadAdditional(tag, registries);
+        items = NonNullList.withSize(SIZE, ItemStack.EMPTY);
+        ContainerHelper.loadAllItems(tag, items, registries);
+        title = tag.getString("Title");
+        pendingAgeId = tag.hasUUID("PendingAgeId") ? tag.getUUID("PendingAgeId") : null;
+    }
+    @Override protected void saveAdditional(CompoundTag tag, HolderLookup.Provider registries) {
+        super.saveAdditional(tag, registries);
+        ContainerHelper.saveAllItems(tag, items, registries);
+        tag.putString("Title", title);
+        if (pendingAgeId != null) tag.putUUID("PendingAgeId", pendingAgeId);
+    }
+    @Override public Packet<ClientGamePacketListener> getUpdatePacket() {
+        return ClientboundBlockEntityDataPacket.create(this);
+    }
+    @Override public CompoundTag getUpdateTag(HolderLookup.Provider registries) {
+        return saveWithoutMetadata(registries);
+    }
+    @Override public void setChanged() {
+        super.setChanged();
+        if (level != null && !level.isClientSide) {
+            level.sendBlockUpdated(worldPosition, getBlockState(), getBlockState(), 2);
+        }
+    }
+}

src/main/java/net/dnorberg/rivencraft/block/entity/WritingDeskBlockEntity.java

@@ -16,18 +16,19 @@ import net.minecraft.world.ContainerHelper;
 import net.minecraft.world.entity.player.Player;
 import net.minecraft.world.item.ItemStack;
 import net.minecraft.world.item.Items;
+import net.minecraft.world.level.Level;
 import net.minecraft.world.level.block.entity.BlockEntity;
 import net.minecraft.world.level.block.state.BlockState;
 
-/** Four collection tabs, paper, ink vials and empty-vial return are owned by the block. */
+/** Collection tabs, paper, ink vials and empty-vial return are owned by the block. */
 public final class WritingDeskBlockEntity extends BlockEntity implements Container {
-    public static final int COLLECTIONS = 4;
+    public static final int COLLECTIONS = 88;
-    public static final int INK = 4;
+    public static final int INK = COLLECTIONS;
-    public static final int RETURN = 5;
+    public static final int RETURN = INK + 1;
-    public static final int PAPER = 6;
+    public static final int PAPER = INK + 2;
     /** Unused by new desks; retained so old saves cannot silently lose slot contents. */
-    public static final int LEGACY_OUTPUT = 7;
+    public static final int LEGACY_OUTPUT = INK + 3;
-    public static final int SIZE = 8;
+    public static final int SIZE = INK + 4;
     private NonNullList<ItemStack> items = NonNullList.withSize(SIZE, ItemStack.EMPTY);
     private int activeCollection;
     private int inkRemaining;
@@ -62,6 +63,7 @@ public final class WritingDeskBlockEntity extends BlockEntity implements Contain
         if (!removed.isEmpty()) {
             if (slot < COLLECTIONS) displayPage = ItemStack.EMPTY;
             setChanged();
+            if (slot == RETURN) refillEmptyInkBar();
         }
         return removed;
     }
@@ -71,6 +73,7 @@ public final class WritingDeskBlockEntity extends BlockEntity implements Contain
         if (stack.getCount() > getMaxStackSize()) stack.setCount(getMaxStackSize());
         if (slot < COLLECTIONS) displayPage = ItemStack.EMPTY;
         setChanged();
+        if (slot == INK || slot == RETURN) refillEmptyInkBar();
     }
     @Override public boolean stillValid(Player player) {
         return level != null && level.isLoaded(worldPosition)
@@ -89,6 +92,28 @@ public final class WritingDeskBlockEntity extends BlockEntity implements Contain
         };
     }
 
+    private boolean hasBottleSpace() {
+        ItemStack returned = items.get(RETURN);
+        return returned.isEmpty() || returned.is(Items.GLASS_BOTTLE)
+                && returned.getCount() < returned.getMaxStackSize();
+    }
+
+    /** Consume one vial only when the empty meter can return its glass bottle. */
+    private void refillEmptyInkBar() {
+        if (level == null || level.isClientSide || inkRemaining != 0 || !hasBottleSpace()) return;
+        ItemStack vial = items.get(INK);
+        if (!vial.is(ModItems.INK_VIAL.get())) return;
+        int ink = Math.clamp(InkVialItem.remaining(vial), 0, InkVialItem.CAPACITY);
+        if (ink == 0) return;
+        inkRemaining = ink;
+        vial.shrink(1);
+        if (vial.isEmpty()) items.set(INK, ItemStack.EMPTY);
+        ItemStack returned = items.get(RETURN);
+        if (returned.isEmpty()) items.set(RETURN, new ItemStack(Items.GLASS_BOTTLE));
+        else returned.grow(1);
+        setChanged();
+    }
+
     /** The output is virtual; inputs are committed only after a result can be given to a player. */
     public boolean canConsumeCopyMaterials() {
         ItemStack paper = items.get(PAPER);
@@ -96,10 +121,8 @@ public final class WritingDeskBlockEntity extends BlockEntity implements Contain
         int cost = WritingInkService.symbolCopyCost();
         if (inkRemaining >= cost) return true;
         ItemStack vial = items.get(INK);
-        ItemStack returned = items.get(RETURN);
         return vial.is(ModItems.INK_VIAL.get()) && inkRemaining + InkVialItem.remaining(vial) >= cost
-                && (returned.isEmpty() || returned.is(Items.GLASS_BOTTLE)
+                && hasBottleSpace();
-                && returned.getCount() < returned.getMaxStackSize());
     }
 
     public boolean consumeCopyMaterials() {
@@ -117,8 +140,13 @@ public final class WritingDeskBlockEntity extends BlockEntity implements Contain
         inkRemaining -= cost;
         removeItem(PAPER, 1);
         setChanged();
+        if (inkRemaining == 0) refillEmptyInkBar();
         return true;
     }
+    @Override public void setLevel(Level level) {
+        super.setLevel(level);
+        refillEmptyInkBar();
+    }
     @Override public void clearContent() {
         items.clear();
         items = NonNullList.withSize(SIZE, ItemStack.EMPTY);
@@ -130,15 +158,25 @@ public final class WritingDeskBlockEntity extends BlockEntity implements Contain
         super.loadAdditional(tag, registries);
         items = NonNullList.withSize(SIZE, ItemStack.EMPTY);
         ContainerHelper.loadAllItems(tag, items, registries);
+        // Pre-88-tab desks stored materials in slots 4..7. Move them once;
+        // never interpret those stacks as newly added collection tabs.
+        if (tag.getInt("InventoryVersion") < 1) {
+            for (int i = 0; i < 4; i++) {
+                items.set(INK + i, items.get(4 + i));
+                items.set(4 + i, ItemStack.EMPTY);
+            }
+        }
         activeCollection = Math.clamp(tag.getInt("ActiveCollection"), 0, COLLECTIONS - 1);
         inkRemaining = Math.clamp(tag.getInt("InkRemaining"), 0, InkVialItem.CAPACITY);
         displayPage = tag.contains("DisplayPage", CompoundTag.TAG_COMPOUND)
                 ? ItemStack.parse(registries, tag.getCompound("DisplayPage")).orElse(ItemStack.EMPTY)
                 : ItemStack.EMPTY;
+        refillEmptyInkBar();
     }
     @Override protected void saveAdditional(CompoundTag tag, HolderLookup.Provider registries) {
         super.saveAdditional(tag, registries);
         ContainerHelper.saveAllItems(tag, items, registries);
+        tag.putInt("InventoryVersion", 1);
         tag.putInt("ActiveCollection", activeCollection);
         tag.putInt("InkRemaining", inkRemaining);
         if (!displayPage.isEmpty()) tag.put("DisplayPage", displayPage.save(registries));

src/main/java/net/dnorberg/rivencraft/client/ClientEvents.java

@@ -15,6 +15,7 @@ import net.neoforged.neoforge.client.event.EntityRenderersEvent;
 import net.neoforged.neoforge.client.event.RegisterMenuScreensEvent;
 import net.dnorberg.rivencraft.client.screen.NotebookScreen;
 import net.dnorberg.rivencraft.client.screen.WritingDeskScreen;
+import net.dnorberg.rivencraft.client.screen.BookBinderScreen;
 import net.dnorberg.rivencraft.registry.ModMenus;
 
 @EventBusSubscriber(modid = Rivencraft.MOD_ID, value = Dist.CLIENT)
@@ -32,6 +33,7 @@ public final class ClientEvents {
     public static void registerScreens(RegisterMenuScreensEvent event) {
         event.register(ModMenus.NOTEBOOK.get(), NotebookScreen::new);
         event.register(ModMenus.WRITING_DESK.get(), WritingDeskScreen::new);
+        event.register(ModMenus.BOOK_BINDER.get(), BookBinderScreen::new);
     }
 
     @SubscribeEvent

src/main/java/net/dnorberg/rivencraft/client/screen/BookBinderScreen.java

@@ -0,0 +1,215 @@
+package net.dnorberg.rivencraft.client.screen;
+
+import net.dnorberg.rivencraft.Rivencraft;
+import net.dnorberg.rivencraft.block.entity.BookBinderBlockEntity;
+import net.dnorberg.rivencraft.item.PageItem;
+import net.dnorberg.rivencraft.menu.BookBinderMenu;
+import net.dnorberg.rivencraft.network.SetBookBinderTitlePayload;
+import net.minecraft.client.gui.GuiGraphics;
+import net.minecraft.client.gui.components.EditBox;
+import net.minecraft.client.gui.screens.inventory.AbstractContainerScreen;
+import net.minecraft.network.chat.Component;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.world.entity.player.Inventory;
+import net.minecraft.world.item.ItemStack;
+import net.neoforged.neoforge.network.PacketDistributor;
+
+/** Legacy-sized binder: cover and result flank a scrolling strip of full page thumbnails. */
+public final class BookBinderScreen extends AbstractContainerScreen<BookBinderMenu> {
+    private static final ResourceLocation BACKGROUND = ResourceLocation.fromNamespaceAndPath(
+            Rivencraft.MOD_ID, "textures/gui/book_binder_legacy.png");
+    private static final ResourceLocation PAGE_ATLAS = ResourceLocation.fromNamespaceAndPath(
+            Rivencraft.MOD_ID, "textures/gui/notebook_pages.png");
+    private static final int STRIP_X = 7;
+    private static final int STRIP_Y = 45;
+    private static final int STRIP_WIDTH = 162;
+    private static final int STRIP_HEIGHT = 40;
+    private static final int PAGE_WIDTH = 26;
+    private static final int PAGE_HEIGHT = 34;
+    private static final int PAGE_STEP = 28;
+    private static final int VISIBLE_PAGES = 5;
+
+    private EditBox titleInput;
+    private int firstVisible;
+    private boolean stripClickPendingRelease;
+
+    public BookBinderScreen(BookBinderMenu menu, Inventory inventory, Component title) {
+        super(menu, inventory, title);
+        imageWidth = 176;
+        imageHeight = 181;
+        inventoryLabelX = 8;
+        inventoryLabelY = 87;
+    }
+
+    @Override protected void init() {
+        super.init();
+        titleInput = new EditBox(font, leftPos + 9, topPos + 10, 112, 12,
+                Component.translatable("screen.rivencraft.book_binder.title"));
+        titleInput.setBordered(false);
+        titleInput.setTextColor(0xFFFFFFFF);
+        titleInput.setMaxLength(BookBinderBlockEntity.MAX_TITLE_LENGTH);
+        titleInput.setValue(menu.title());
+        titleInput.setHint(Component.translatable("screen.rivencraft.book_binder.title_hint"));
+        titleInput.setResponder(value -> PacketDistributor.sendToServer(
+                new SetBookBinderTitlePayload(menu.containerId, value)));
+        addRenderableWidget(titleInput);
+    }
+
+    @Override public void renderBackground(GuiGraphics graphics, int mouseX, int mouseY, float partialTick) {
+        renderBg(graphics, partialTick, mouseX, mouseY);
+    }
+
+    @Override protected void renderBg(GuiGraphics graphics, float partialTick, int mouseX, int mouseY) {
+        graphics.blit(BACKGROUND, leftPos, topPos, 0, 0, imageWidth, imageHeight, 256, 256);
+        if (menu.getSlot(BookBinderBlockEntity.LINK_PANEL).getItem().isEmpty()) {
+            float fade = (System.currentTimeMillis() % 4000L) / 2000F;
+            if (fade > 1F) fade = 2F - fade;
+            graphics.blit(BACKGROUND, leftPos + 27, topPos + 26,
+                    18, 18, 176, 0, 30, 40, 256, 256);
+            graphics.setColor(1F, 0.3F, 0.3F, 0.8F * fade);
+            graphics.blit(BACKGROUND, leftPos + 27, topPos + 26,
+                    18, 18, 176, 0, 30, 40, 256, 256);
+            graphics.setColor(1F, 1F, 1F, 1F);
+        }
+        graphics.fill(leftPos + 7, topPos + 9, leftPos + 123, topPos + 23, 0xFF000000);
+        graphics.renderOutline(leftPos + 7, topPos + 9, 116, 14,
+                titleInput == null || titleInput.getValue().isBlank() ? 0xFFFF3030 : 0xFFA0A0A0);
+    }
+
+    @Override protected void renderLabels(GuiGraphics graphics, int mouseX, int mouseY) {
+        graphics.drawString(font, playerInventoryTitle, inventoryLabelX, inventoryLabelY, 0xFF404040, false);
+    }
+
+    @Override public void render(GuiGraphics graphics, int mouseX, int mouseY, float partialTick) {
+        super.render(graphics, mouseX, mouseY, partialTick);
+        firstVisible = Math.min(firstVisible, maxFirstVisible());
+        graphics.enableScissor(leftPos + STRIP_X + 8, topPos + STRIP_Y,
+                leftPos + STRIP_X + STRIP_WIDTH - 8, topPos + STRIP_Y + STRIP_HEIGHT);
+        int count = visiblePageCount();
+        for (int visible = 0; visible < VISIBLE_PAGES; visible++) {
+            int index = firstVisible + visible;
+            if (index >= count) break;
+            drawPage(graphics, pageAtIndex(index), index,
+                    leftPos + 16 + visible * PAGE_STEP, topPos + STRIP_Y + 3);
+        }
+        graphics.disableScissor();
+        drawScrollEnds(graphics);
+        if (pageAtIndex(0).isEmpty() && mouseX >= leftPos + 27 && mouseX < leftPos + 45
+                && mouseY >= topPos + 26 && mouseY < topPos + 44) {
+            graphics.renderTooltip(font,
+                    Component.translatable("screen.rivencraft.book_binder.missing_panel"), mouseX, mouseY);
+            return;
+        }
+        int hovered = pageIndexAt(mouseX, mouseY);
+        if (hovered >= 0 && hovered < displayedPages() && !pageAtIndex(hovered).isEmpty())
+            graphics.renderTooltip(font, pageAtIndex(hovered), mouseX, mouseY);
+        else renderTooltip(graphics, mouseX, mouseY);
+    }
+
+    private ItemStack pageAtIndex(int index) {
+        return menu.getSlot(index == 0 ? BookBinderBlockEntity.LINK_PANEL
+                : BookBinderBlockEntity.FIRST_PAGE + index - 1).getItem();
+    }
+
+    private int displayedPages() {
+        for (int index = BookBinderBlockEntity.PAGE_COUNT; index >= 1; index--)
+            if (!pageAtIndex(index).isEmpty()) return index + 1;
+        return pageAtIndex(0).isEmpty() ? 0 : 1;
+    }
+
+    private int maxFirstVisible() {
+        return Math.max(0, visiblePageCount() - VISIBLE_PAGES);
+    }
+
+    private int visiblePageCount() {
+        return Math.min(BookBinderBlockEntity.PAGE_COUNT + 1,
+                displayedPages() + (menu.getCarried().isEmpty() ? 0 : 1));
+    }
+
+    private void drawPage(GuiGraphics graphics, ItemStack page, int index, int x, int y) {
+        graphics.blit(PAGE_ATLAS, x, y, PAGE_WIDTH, PAGE_HEIGHT, 156, 0, 30, 40, 256, 256);
+        if (page.isEmpty()) {
+            graphics.fill(x, y, x + PAGE_WIDTH, y + PAGE_HEIGHT, 0xAA000000);
+            return;
+        }
+        switch (PageItem.content(page).kind()) {
+            case BLANK -> { }
+            case LINK_PANEL -> graphics.fill(x + 5, y + 6, x + 22, y + 17, 0xFF000000);
+            case SYMBOL, UNRESOLVED_SYMBOL -> graphics.blit(NotebookScreen.symbolTexture(page),
+                    x + 1, y + 5, 24, 24, 16, 16, 96, 96, 128, 128);
+        }
+    }
+
+    private void drawScrollEnds(GuiGraphics graphics) {
+        int x = leftPos + STRIP_X;
+        int y = topPos + STRIP_Y;
+        graphics.fill(x, y, x + 8, y + STRIP_HEIGHT,
+                firstVisible == 0 ? 0x33000000 : 0xAA000000);
+        graphics.fill(x + STRIP_WIDTH - 8, y, x + STRIP_WIDTH, y + STRIP_HEIGHT,
+                firstVisible >= maxFirstVisible() ? 0x33000000 : 0xAA000000);
+    }
+
+    private int pageIndexAt(double mouseX, double mouseY) {
+        int localX = (int) mouseX - leftPos;
+        int localY = (int) mouseY - topPos;
+        if (localX < STRIP_X + 8 || localX >= STRIP_X + STRIP_WIDTH - 8
+                || localY < STRIP_Y || localY >= STRIP_Y + STRIP_HEIGHT) return -1;
+        int visible = (localX - 16) / PAGE_STEP;
+        if (visible < 0 || visible >= VISIBLE_PAGES) return -1;
+        return Math.min(firstVisible + visible, BookBinderBlockEntity.PAGE_COUNT);
+    }
+
+    @Override public boolean mouseClicked(double mouseX, double mouseY, int button) {
+        int localX = (int) mouseX - leftPos;
+        int localY = (int) mouseY - topPos;
+        if ((button == 0 || button == 1) && localY >= STRIP_Y && localY < STRIP_Y + STRIP_HEIGHT
+                && localX >= STRIP_X && localX < STRIP_X + STRIP_WIDTH) {
+            stripClickPendingRelease = true;
+            if (localX < STRIP_X + 8) firstVisible = Math.max(0, firstVisible - 1);
+            else if (localX >= STRIP_X + STRIP_WIDTH - 8)
+                firstVisible = Math.min(maxFirstVisible(), firstVisible + 1);
+            else {
+                int index = pageIndexAt(mouseX, mouseY);
+                if (index >= 0 && index <= displayedPages()
+                        && (index < displayedPages() || !menu.getCarried().isEmpty()))
+                    clickStrip(index);
+            }
+            return true;
+        }
+        return super.mouseClicked(mouseX, mouseY, button);
+    }
+
+    private void clickStrip(int index) {
+        if (minecraft != null && minecraft.gameMode != null)
+            minecraft.gameMode.handleInventoryButtonClick(menu.containerId,
+                    BookBinderMenu.STRIP_CLICK_BASE + index);
+    }
+
+    @Override public boolean mouseReleased(double mouseX, double mouseY, int button) {
+        if (stripClickPendingRelease) {
+            stripClickPendingRelease = false;
+            return true;
+        }
+        return super.mouseReleased(mouseX, mouseY, button);
+    }
+
+    @Override public boolean mouseScrolled(double mouseX, double mouseY, double scrollX, double scrollY) {
+        if (mouseX >= leftPos + STRIP_X && mouseX < leftPos + STRIP_X + STRIP_WIDTH
+                && mouseY >= topPos + STRIP_Y && mouseY < topPos + STRIP_Y + STRIP_HEIGHT) {
+            firstVisible = Math.clamp(firstVisible - (int) Math.signum(scrollY), 0, maxFirstVisible());
+            return true;
+        }
+        return super.mouseScrolled(mouseX, mouseY, scrollX, scrollY);
+    }
+
+    @Override public boolean keyPressed(int keyCode, int scanCode, int modifiers) {
+        if (titleInput != null && titleInput.isFocused()) {
+            if (keyCode == 256) {
+                setFocused(null);
+                titleInput.setFocused(false);
+            } else titleInput.keyPressed(keyCode, scanCode, modifiers);
+            return true;
+        }
+        return super.keyPressed(keyCode, scanCode, modifiers);
+    }
+}

src/main/java/net/dnorberg/rivencraft/client/screen/WritingDeskScreen.java

@@ -2,10 +2,12 @@ package net.dnorberg.rivencraft.client.screen;
 
 import java.util.List;
 import java.util.Locale;
-import java.util.Objects;
+import java.util.ArrayList;
+import java.util.Comparator;
 import net.dnorberg.rivencraft.Rivencraft;
 import net.dnorberg.rivencraft.item.PageItem;
 import net.dnorberg.rivencraft.menu.WritingDeskMenu;
+import net.dnorberg.rivencraft.block.entity.WritingDeskBlockEntity;
 import net.dnorberg.rivencraft.registry.ModDataComponents;
 import net.dnorberg.rivencraft.registry.ModItems;
 import net.dnorberg.rivencraft.writing.NotebookContents;
@@ -17,68 +19,109 @@ import net.minecraft.client.gui.screens.inventory.AbstractContainerScreen;
 import net.minecraft.network.chat.Component;
 import net.minecraft.resources.ResourceLocation;
 import net.minecraft.world.entity.player.Inventory;
+import net.minecraft.world.inventory.Slot;
 import net.minecraft.world.item.ItemStack;
 
-/** Functional storage surface; full Legacy transcription controls are a later Milestone 4 slice. */
+/** Legacy desk atlas layout, with four visible tabs out of the desk's 88 collections. */
 public final class WritingDeskScreen extends AbstractContainerScreen<WritingDeskMenu> {
     private static final ResourceLocation PAGE_ATLAS = ResourceLocation.fromNamespaceAndPath(
             Rivencraft.MOD_ID, "textures/gui/notebook_pages.png");
     private static final ResourceLocation LEGACY_DESK = ResourceLocation.fromNamespaceAndPath(
             Rivencraft.MOD_ID, "textures/gui/writing_desk_legacy.png");
+    private static final ResourceLocation SCROLLBAR = ResourceLocation.fromNamespaceAndPath(
+            Rivencraft.MOD_ID, "textures/gui/scrollbar.png");
     private int lastCollection = -1;
     private int selectedPage;
     private int scrollRows;
     private boolean allMode;
-    private ResourceLocation selectedSymbol;
+    private boolean sortAlphabetically;
+    private int selectedCollection = -1;
     private ResourceLocation selectedCategory;
     private EditBox search;
     private Button categoryButton;
+    private Button allButton;
+    private Button sortButton;
+    private boolean draggingScrollbar;
+    private record DisplayPage(int collection, int index, ItemStack stack) {}
+    private DisplayPage pageDragSource;
+    private double pageDragStartX;
+    private double pageDragStartY;
+    private boolean draggingPage;
+
+    private boolean isPhysicalPageView() {
+        return !allMode && !sortAlphabetically && selectedCategory == null
+                && (search == null || search.getValue().isBlank());
+    }
 
     public WritingDeskScreen(WritingDeskMenu menu, Inventory inventory, Component title) {
         super(menu, inventory, title);
-        imageWidth = 398;
+        imageWidth = 409;
-        imageHeight = 176;
+        imageHeight = 186;
         titleLabelX = 222;
-        inventoryLabelX = 224;
-        inventoryLabelY = 79;
     }
 
     @Override protected void init() {
         super.init();
-        addRenderableWidget(Button.builder(Component.literal("ALL"), button -> {
+        sortButton = addRenderableWidget(Button.builder(Component.literal("AZ"), button -> {
-            allMode = true;
+            sortAlphabetically = !sortAlphabetically;
             scrollRows = 0;
-        }).bounds(leftPos + 48, topPos - 18, 29, 18).build());
+        }).bounds(leftPos + 58, topPos, 20, 18).build());
-        categoryButton = addRenderableWidget(Button.builder(Component.literal("All types"), button -> {
+        allButton = addRenderableWidget(Button.builder(Component.literal("ALL"), button -> {
+            allMode = !allMode;
+            scrollRows = 0;
+            if (!allMode) {
+                selectedCollection = -1;
+                selectedPage = 0;
+                if (minecraft != null && minecraft.gameMode != null)
+                    minecraft.gameMode.handleInventoryButtonClick(menu.containerId, WritingDeskMenu.PAGE_BUTTON_BASE);
+            }
+        }).bounds(leftPos + 80, topPos, 28, 18).build());
+        search = new EditBox(font, leftPos + 110, topPos, 101, 18,
+                Component.translatable("screen.rivencraft.writing_desk.search"));
+        search.setMaxLength(64);
+        search.setHint(Component.translatable("screen.rivencraft.writing_desk.search"));
+        search.setResponder(value -> scrollRows = 0);
+        addRenderableWidget(search);
+        categoryButton = addRenderableWidget(Button.builder(Component.literal("C"), button -> {
             List<ResourceLocation> categories = menu.catalog().stream()
                     .map(SymbolDisplayMetadata::category).distinct().sorted().toList();
             int next = selectedCategory == null ? 0 : categories.indexOf(selectedCategory) + 1;
             selectedCategory = next >= categories.size() ? null : categories.get(next);
-            categoryButton.setMessage(Component.literal(selectedCategory == null
+            categoryButton.setMessage(Component.literal(selectedCategory == null ? "C" : "C*"));
-                    ? "All types" : selectedCategory.getPath()));
-            allMode = true;
             scrollRows = 0;
-        }).bounds(leftPos + 79, topPos - 18, 66, 18).build());
+        }).bounds(leftPos + 213, topPos, 18, 18).build());
-        search = new EditBox(font, leftPos + 147, topPos - 18, 69, 18,
-                Component.translatable("screen.rivencraft.writing_desk.search"));
-        search.setMaxLength(64);
-        search.setHint(Component.translatable("screen.rivencraft.writing_desk.search"));
-        search.setResponder(value -> {
-            allMode = true;
-            scrollRows = 0;
-        });
-        addRenderableWidget(search);
     }
 
-    private List<SymbolDisplayMetadata> filteredCatalog() {
+    private List<DisplayPage> filteredPages() {
         String query = search == null ? "" : search.getValue().trim().toLowerCase(Locale.ROOT);
-        return menu.catalog().stream()
+        List<DisplayPage> entries = new ArrayList<>();
-                .filter(entry -> selectedCategory == null || selectedCategory.equals(entry.category()))
+        int from = allMode ? 0 : menu.activeCollection();
-                .filter(entry -> query.isEmpty()
+        int until = allMode ? WritingDeskBlockEntity.COLLECTIONS : from + 1;
-                        || entry.id().toString().toLowerCase(Locale.ROOT).contains(query)
+        for (int collection = from; collection < until; collection++) {
-                        || Component.translatable(entry.nameTranslationKey()).getString()
+            List<ItemStack> pages = pages(collection);
-                        .toLowerCase(Locale.ROOT).contains(query))
+            int last = -1;
-                .toList();
+            for (int i = 0; i < pages.size(); i++) if (!pages.get(i).isEmpty()) last = i;
+            // A notebook has exactly its normal GUI capacity; a loose page has one position.
+            if (isPhysicalPageView()) last = menu.pageCapacity(collection) - 1;
+            for (int i = 0; i <= last; i++) {
+                ItemStack page = i < pages.size() ? pages.get(i) : ItemStack.EMPTY;
+                if (page.isEmpty() && (allMode || sortAlphabetically || !query.isEmpty() || selectedCategory != null)) continue;
+                if (!page.isEmpty() && !query.isEmpty()
+                        && !page.getHoverName().getString().toLowerCase(Locale.ROOT).contains(query)
+                        && !PageItem.content(page).symbol().map(symbol -> symbol.id().toString()
+                        .toLowerCase(Locale.ROOT).contains(query)).orElse(false)) continue;
+                if (!page.isEmpty() && selectedCategory != null) {
+                    ResourceLocation id = PageItem.content(page).symbol().map(symbol -> symbol.id()).orElse(null);
+                    if (menu.catalog().stream().noneMatch(metadata -> metadata.id().equals(id)
+                            && metadata.category().equals(selectedCategory))) continue;
+                }
+                entries.add(new DisplayPage(collection, i, page));
+            }
+        }
+        if (sortAlphabetically) entries.sort(Comparator
+                .comparing((DisplayPage entry) -> entry.stack().getHoverName().getString(), String.CASE_INSENSITIVE_ORDER)
+                .thenComparingInt(DisplayPage::collection).thenComparingInt(DisplayPage::index));
+        return entries;
     }
 
     @Override public void renderBackground(GuiGraphics graphics, int mouseX, int mouseY, float partialTick) {
@@ -90,54 +133,83 @@ public final class WritingDeskScreen extends AbstractContainerScreen<WritingDesk
     @Override protected void renderBg(GuiGraphics graphics, float partialTick, int mouseX, int mouseY) {
         int x = leftPos;
         int y = topPos;
-        // Use textured backing: GUI fills may depth-test behind the world with some renderers.
+        // Legacy GuiWritingDesk draws the entire 176x166 panel, not a stretched swatch.
-        graphics.blit(LEGACY_DESK, x + 218, y + 4, 178, 170, 64, 8, 16, 16, 256, 256);
+        graphics.blit(LEGACY_DESK, x + 233, y + 20, 0, 0, 176, 166);
+        drawTabControl(graphics, 20, 203, menu.firstVisibleTab() > 0);
         for (int i = 0; i < 4; i++) {
-            graphics.blit(LEGACY_DESK, x + 6, y + 16 + i * 37,
+            int tab = menu.firstVisibleTab() + i;
-                    34, 32, 0, 166, 56, 54, 256, 256);
+            int tabY = y + 29 + i * 37;
-            if (i == menu.activeCollection())
+            if (tab == menu.activeCollection() && !allMode) graphics.setColor(0.5F, 0.5F, 1F, 1F);
-                graphics.renderOutline(x + 6, y + 16 + i * 37, 34, 32, 0xFF7777B6);
+            graphics.blit(LEGACY_DESK, x, tabY, 0, 166, 58, 37);
-            slotFrame(graphics, 12, 20 + i * 37);
+            graphics.setColor(1F, 1F, 1F, 1F);
+            graphics.drawString(font, Integer.toString(tab + 1), x + 8, tabY + 8, 0xFF181818, false);
+            ItemStack collection = menu.getSlot(tab).getItem();
+            if (!collection.isEmpty()) {
+                String name = collection.getHoverName().getString();
+                float scale = Math.min(1F, 50F / Math.max(1, font.width(name)));
+                graphics.pose().pushPose();
+                graphics.pose().translate(x + 4, tabY + 25, 0);
+                graphics.pose().scale(scale, scale, 1);
+                graphics.drawString(font, name, 0, 0, 0xFF404040, false);
+                graphics.pose().popPose();
+            }
         }
-        slotFrame(graphics, 370, 20);
+        drawTabControl(graphics, 177, 212, menu.firstVisibleTab() < WritingDeskBlockEntity.COLLECTIONS - 4);
-        slotFrame(graphics, 228, 20);
+        // GuiElementVSlider: 4-pixel caps, repeated 22-pixel track, 12x15 thumb.
-        slotFrame(graphics, 228, 57);
+        graphics.blit(SCROLLBAR, x + 213, y + 20, 0, 0, 20, 4, 32, 32);
-        slotFrame(graphics, 370, 57);
+        for (int offset = 4; offset < 162; offset += 22)
-        graphics.fill(x + 350, y + 20, x + 364, y + 75, 0xFF303035);
+            graphics.blit(SCROLLBAR, x + 213, y + 20 + offset, 0, 4, 20, Math.min(22, 162 - offset), 32, 32);
-        graphics.fill(x + 352, y + 22, x + 362, y + 73, 0xFF15151B);
+        graphics.blit(SCROLLBAR, x + 213, y + 182, 0, 26, 20, 4, 32, 32);
-        int filled = 51 * menu.inkRemaining() / 16;
+        int totalRows = (filteredPages().size() + 4) / 5;
-        if (filled > 0) graphics.fill(x + 352, y + 73 - filled, x + 362, y + 73, 0xFF6666AA);
+        int maxScroll = Math.max(0, totalRows - 4);
-        graphics.renderOutline(x + 350, y + 20, 14, 55, 0xFF484848);
+        scrollRows = Math.clamp(scrollRows, 0, maxScroll);
-        for (int row = 0; row < 3; row++) {
+        int thumbY = y + 24 + (maxScroll == 0 ? 0 : scrollRows * 143 / maxScroll);
-            for (int column = 0; column < 9; column++) slotFrame(graphics, 224 + column * 18, 91 + row * 18);
+        graphics.blit(SCROLLBAR, x + 217, thumbY, 20, draggingScrollbar ? 15 : 0, 12, 15, 32, 32);
-        }
+        graphics.fill(x + 365, y + 27, x + 381, y + 97, 0xFF303035);
-        for (int column = 0; column < 9; column++) slotFrame(graphics, 224 + column * 18, 149);
+        graphics.fill(x + 366, y + 28, x + 380, y + 96, 0xFF6666AA);
+        int filled = 68 * menu.inkRemaining() / 16;
+        if (filled > 0) graphics.fill(x + 366, y + 96 - filled, x + 380, y + 96, 0xFF15151B);
     }
 
-    private void slotFrame(GuiGraphics graphics, int x, int y) {
+    private void drawTabControl(GuiGraphics graphics, int y, int textureY, boolean enabled) {
-        graphics.fill(leftPos + x - 1, topPos + y - 1,
+        if (!enabled) graphics.setColor(0.4F, 0.4F, 0.4F, 1F);
-                leftPos + x + 17, topPos + y + 17, 0xFF4D4D4D);
+        graphics.blit(LEGACY_DESK, leftPos, topPos + y, 0, textureY, 58, 9);
-        graphics.fill(leftPos + x, topPos + y,
+        graphics.setColor(1F, 1F, 1F, 1F);
-                leftPos + x + 16, topPos + y + 16, 0xFF858585);
     }
 
     @Override protected void renderLabels(GuiGraphics graphics, int mouseX, int mouseY) {
-        graphics.drawString(font, playerInventoryTitle, inventoryLabelX, inventoryLabelY, 0x404040, false);
+        // Legacy leaves the inventory grid unlabeled.
     }
 
     @Override public void render(GuiGraphics graphics, int mouseX, int mouseY, float partialTick) {
         super.render(graphics, mouseX, mouseY, partialTick);
+        if (sortAlphabetically) graphics.renderOutline(leftPos + 58, topPos, 20, 18, 0xFFFFD061);
+        if (allMode) graphics.renderOutline(leftPos + 80, topPos, 28, 18, 0xFFFFD061);
         renderCollection(graphics);
+        if (draggingPage && pageDragSource != null) {
+            DisplayPage target = pageAtMouse(mouseX, mouseY);
+            if (target != null && canMovePage(pageDragSource, target)) {
+                int x = leftPos + 58 + ((int) mouseX - leftPos - 58) / 31 * 31;
+                int y = topPos + 20 + ((int) mouseY - topPos - 20) / 41 * 41;
+                graphics.renderOutline(x, y, 30, 40, 0xFF57D478);
+            }
+            graphics.renderItem(pageDragSource.stack(), mouseX - 8, mouseY - 8);
+        }
         renderTooltip(graphics, mouseX, mouseY);
-        if (mouseX >= leftPos + 350 && mouseX < leftPos + 364
+        if (mouseX >= leftPos + 365 && mouseX < leftPos + 381
-                && mouseY >= topPos + 20 && mouseY < topPos + 75) {
+                && mouseY >= topPos + 27 && mouseY < topPos + 97) {
             graphics.renderTooltip(font, Component.translatable("screen.rivencraft.writing_desk.ink",
                     menu.inkRemaining(), 16), mouseX, mouseY);
         }
+        if (mouseX >= leftPos + 213 && mouseX < leftPos + 231
+                && mouseY >= topPos && mouseY < topPos + 18) {
+            graphics.renderTooltip(font, Component.literal(selectedCategory == null
+                    ? "All categories" : selectedCategory.toString()), mouseX, mouseY);
+        }
     }
 
-    private List<ItemStack> pages() {
+    private List<ItemStack> pages(int collectionIndex) {
-        ItemStack collection = menu.getSlot(menu.activeCollection()).getItem();
+        ItemStack collection = menu.getSlot(collectionIndex).getItem();
         if (collection.is(ModItems.PAGE.get())) return List.of(collection);
         if (collection.is(ModItems.NOTEBOOK.get())) {
             return collection.getOrDefault(ModDataComponents.NOTEBOOK_CONTENTS.get(), NotebookContents.EMPTY).pages();
@@ -146,73 +218,34 @@ public final class WritingDeskScreen extends AbstractContainerScreen<WritingDesk
     }
 
     private void renderCollection(GuiGraphics graphics) {
-        if (allMode) {
-            renderCatalog(graphics);
-            return;
-        }
-        List<ItemStack> pages = pages();
         if (lastCollection != menu.activeCollection()) {
             lastCollection = menu.activeCollection();
             scrollRows = 0;
             selectedPage = 0;
+            selectedCollection = -1;
         }
-        int last = -1;
+        List<DisplayPage> entries = filteredPages();
-        for (int i = 0; i < pages.size(); i++) if (!pages.get(i).isEmpty()) last = i;
+        for (int i = scrollRows * 5; i < entries.size() && i < scrollRows * 5 + 20; i++) {
-        for (int i = scrollRows * 5; i <= last && i < scrollRows * 5 + 15; i++) {
             int column = i % 5;
             int row = i / 5 - scrollRows;
-            ItemStack page = pages.get(i);
+            DisplayPage entry = entries.get(i);
-            int x = leftPos + 48 + column * 31;
+            ItemStack page = entry.stack();
-            int y = topPos + 18 + row * 41;
+            int x = leftPos + 58 + column * 31;
+            int y = topPos + 20 + row * 41;
             drawPage(graphics, page, x, y);
             if (page.isEmpty()) graphics.fill(x, y, x + 30, y + 40, 0xB8000000);
-            if (i == selectedPage && !page.isEmpty()) graphics.renderOutline(x, y, 30, 40, 0xFFFFD061);
+            int active = selectedCollection >= 0 ? selectedCollection : menu.activeCollection();
-        }
+            if (entry.collection() == active && entry.index() == selectedPage && !page.isEmpty())
-        if (selectedPage >= pages.size() || pages.get(selectedPage).isEmpty()) return;
-        ItemStack selected = pages.get(selectedPage);
-        graphics.pose().pushPose();
-        graphics.pose().translate(leftPos + 294, topPos + 12, 0);
-        graphics.pose().scale(1.35F, 1.35F, 1.0F);
-        drawPage(graphics, selected, 0, 0);
-        graphics.pose().popPose();
-        String title = font.plainSubstrByWidth(selected.getHoverName().getString(), 112);
-        graphics.fill(leftPos + 251, topPos + 64, leftPos + 365, topPos + 77, 0xFF202020);
-        graphics.drawString(font, title, leftPos + 254, topPos + 67, 0xFFE0E0E0, false);
-    }
-
-    private void renderCatalog(GuiGraphics graphics) {
-        List<SymbolDisplayMetadata> filtered = filteredCatalog();
-        if (filtered.isEmpty()) {
-            graphics.drawString(font, Component.translatable("screen.rivencraft.writing_desk.no_symbols"),
-                    leftPos + 52, topPos + 24, 0xFFC4B8A3, false);
-        }
-        for (int i = scrollRows * 5; i < filtered.size() && i < scrollRows * 5 + 15; i++) {
-            SymbolDisplayMetadata entry = filtered.get(i);
-            int x = leftPos + 48 + (i % 5) * 31;
-            int y = topPos + 18 + (i / 5 - scrollRows) * 41;
-            drawSymbolPage(graphics, entry.id(), x, y);
-            if (Objects.equals(entry.id(), selectedSymbol)) {
                 graphics.renderOutline(x, y, 30, 40, 0xFFFFD061);
-            }
         }
-        SymbolDisplayMetadata selected = menu.catalog().stream()
+        int active = selectedCollection >= 0 ? selectedCollection : menu.activeCollection();
-                .filter(entry -> Objects.equals(entry.id(), selectedSymbol)).findFirst().orElse(null);
+        List<ItemStack> source = pages(active);
-        if (selected == null) return;
+        if (selectedPage >= source.size() || source.get(selectedPage).isEmpty()) return;
-        graphics.pose().pushPose();
+        ItemStack selected = source.get(selectedPage);
-        graphics.pose().translate(leftPos + 294, topPos + 12, 0);
+        drawPage(graphics, selected, leftPos + 265, topPos + 26);
-        graphics.pose().scale(1.35F, 1.35F, 1.0F);
+        String title = font.plainSubstrByWidth(selected.getHoverName().getString(), 95);
-        drawSymbolPage(graphics, selected.id(), 0, 0);
+        graphics.fill(leftPos + 261, topPos + 81, leftPos + 360, topPos + 95, 0xFF202020);
-        graphics.pose().popPose();
+        graphics.drawString(font, title, leftPos + 263, topPos + 84, 0xFFE0E0E0, false);
-        String title = font.plainSubstrByWidth(
-                Component.translatable(selected.nameTranslationKey()).getString(), 112);
-        graphics.fill(leftPos + 251, topPos + 64, leftPos + 365, topPos + 77, 0xFF202020);
-        graphics.drawString(font, title, leftPos + 254, topPos + 67, 0xFFE0E0E0, false);
-    }
-
-    private void drawSymbolPage(GuiGraphics graphics, ResourceLocation id, int x, int y) {
-        graphics.blit(PAGE_ATLAS, x, y, 30, 40, 156, 0, 30, 40, 256, 256);
-        graphics.blit(NotebookScreen.symbolTexture(id), x + 1, y + 6,
-                28, 28, 16, 16, 96, 96, 128, 128);
     }
 
     private void drawPage(GuiGraphics graphics, ItemStack page, int x, int y) {
@@ -226,45 +259,116 @@ public final class WritingDeskScreen extends AbstractContainerScreen<WritingDesk
         }
     }
 
+    private DisplayPage pageAtMouse(double mouseX, double mouseY) {
+        int x = (int) Math.floor(mouseX - leftPos - 58);
+        int y = (int) Math.floor(mouseY - topPos - 20);
+        if (x < 0 || x >= 155 || y < 0 || y >= 164 || x % 31 >= 30 || y % 41 >= 40) return null;
+        int index = (y / 41 + scrollRows) * 5 + x / 31;
+        List<DisplayPage> entries = filteredPages();
+        return index < entries.size() ? entries.get(index) : null;
+    }
+
+    private boolean canMovePage(DisplayPage source, DisplayPage target) {
+        return !source.stack().isEmpty()
+                && (menu.getSlot(source.collection()).getItem().is(ModItems.NOTEBOOK.get())
+                    || menu.getSlot(source.collection()).getItem().is(ModItems.PAGE.get()))
+                && (menu.getSlot(target.collection()).getItem().is(ModItems.NOTEBOOK.get())
+                    || menu.getSlot(target.collection()).getItem().is(ModItems.PAGE.get()))
+                && (source.collection() != target.collection() || source.index() != target.index());
+    }
+
+    private int extractTargetSlot(double mouseX, double mouseY) {
+        for (Slot slot : menu.slots) {
+            int index = slot.index;
+            if (index >= WritingDeskBlockEntity.COLLECTIONS && index <= WritingDeskMenu.COPY_RESULT) continue;
+            if (!slot.isActive() || !isHovering(slot.x, slot.y, 16, 16, mouseX, mouseY)) continue;
+            ItemStack held = pageDragSource.stack();
+            if (!slot.mayPlace(held)) return -1;
+            ItemStack current = slot.getItem();
+            if (current.isEmpty()) return index;
+            if (index < WritingDeskBlockEntity.COLLECTIONS && current.is(ModItems.NOTEBOOK.get())) {
+                List<ItemStack> pages = current.getOrDefault(
+                        ModDataComponents.NOTEBOOK_CONTENTS.get(), NotebookContents.EMPTY).pages();
+                if (pages.size() < NotebookContents.MAX_PAGES || pages.stream().anyMatch(ItemStack::isEmpty))
+                    return index;
+            } else if (index > WritingDeskMenu.COPY_RESULT && ItemStack.isSameItemSameComponents(current, held)
+                    && current.getCount() < slot.getMaxStackSize(held)) return index;
+            return -1;
+        }
+        return -1;
+    }
+
     @Override public boolean mouseClicked(double mouseX, double mouseY, int button) {
         if (button == 0) {
-            int x = (int) mouseX - leftPos - 48;
+            pageDragSource = null;
-            int y = (int) mouseY - topPos - 18;
+            draggingPage = false;
-            if (x >= 0 && x < 155 && y >= 0 && y < 123) {
+        }
-                int column = x / 31;
+        int surfaceX = (int) Math.floor(mouseX - leftPos - 58);
-                int row = y / 41;
+        int surfaceY = (int) Math.floor(mouseY - topPos - 20);
-                int index = (row + scrollRows) * 5 + column;
+        if ((button == 0 || button == 1) && !menu.getCarried().isEmpty()
-                if (allMode) {
+                && surfaceX >= 0 && surfaceX < 155 && surfaceY >= 0 && surfaceY < 164) {
-                    List<SymbolDisplayMetadata> filtered = filteredCatalog();
+            if (menu.getCarried().is(ModItems.PAGE.get()) && surfaceX % 31 < 30 && surfaceY % 41 < 40) {
-                    if (x % 31 < 30 && y % 41 < 40 && index < filtered.size()) {
+                int index = (surfaceY / 41 + scrollRows) * 5 + surfaceX / 31;
-                        SymbolDisplayMetadata entry = filtered.get(index);
+                List<DisplayPage> entries = filteredPages();
-                        selectedSymbol = entry.id();
+                // Only displayed positions are addressable. Filtering never turns
-                        int serverIndex = menu.catalog().indexOf(entry);
+                // empty screen space into additional storage for a loose-page tab.
-                        if (serverIndex >= 0 && minecraft != null && minecraft.gameMode != null) {
+                int collection = index < entries.size() ? entries.get(index).collection() : menu.activeCollection();
-                            minecraft.gameMode.handleInventoryButtonClick(menu.containerId, 100 + serverIndex);
+                int page = index < entries.size() ? entries.get(index).index() : index;
-                        }
+                if (index < entries.size() && page < menu.pageCapacity(collection)
+                        && minecraft != null && minecraft.gameMode != null) {
+                    minecraft.gameMode.handleInventoryButtonClick(menu.containerId,
+                            WritingDeskMenu.PLACE_PAGE_BUTTON_BASE + collection * NotebookContents.MAX_PAGES + page);
+                }
+            }
+            return true;
+        }
+        if (button == 0) {
+            if (mouseX >= leftPos && mouseX < leftPos + 58) {
+                int y = (int) mouseY - topPos;
+                if (y >= 20 && y < 29 || y >= 177 && y < 186) {
+                    if (minecraft != null && minecraft.gameMode != null)
+                        minecraft.gameMode.handleInventoryButtonClick(menu.containerId,
+                                y < 29 ? WritingDeskMenu.PREVIOUS_TABS : WritingDeskMenu.NEXT_TABS);
+                    return true;
+                }
+            }
+            if (mouseX >= leftPos + 213 && mouseX < leftPos + 233
+                    && mouseY >= topPos + 20 && mouseY < topPos + 186) {
+                draggingScrollbar = true;
+                setScrollFromMouse(mouseY);
+                return true;
+            }
+            int x = (int) Math.floor(mouseX - leftPos - 58);
+            int y = (int) Math.floor(mouseY - topPos - 20);
+            if (x >= 0 && x < 155 && y >= 0 && y < 164) {
+                DisplayPage entry = pageAtMouse(mouseX, mouseY);
+                if (entry != null && !entry.stack().isEmpty()) {
+                    selectedCollection = entry.collection();
+                    selectedPage = entry.index();
+                    if (menu.getCarried().isEmpty()) {
+                        pageDragSource = entry;
+                        pageDragStartX = mouseX;
+                        pageDragStartY = mouseY;
                     }
-                } else {
+                    if (minecraft != null && minecraft.gameMode != null) {
-                    List<ItemStack> pages = pages();
+                        int id = WritingDeskMenu.ALL_PAGE_BUTTON_BASE
-                    if (x % 31 < 30 && y % 41 < 40 && index < pages.size()
+                                + entry.collection() * NotebookContents.MAX_PAGES + entry.index();
-                            && !pages.get(index).isEmpty()) {
+                        minecraft.gameMode.handleInventoryButtonClick(menu.containerId, id);
-                        selectedPage = index;
-                        if (minecraft != null && minecraft.gameMode != null) {
-                            minecraft.gameMode.handleInventoryButtonClick(menu.containerId, 16 + index);
-                        }
                     }
                 }
                 return true;
             }
         }
-        if (button == 0 && mouseX >= leftPos + 29 && mouseX < leftPos + 40) {
+        if (button == 0 && mouseX >= leftPos && mouseX < leftPos + 58) {
             for (int i = 0; i < 4; i++) {
-                int top = topPos + 16 + i * 37;
+                int top = topPos + 29 + i * 37;
-                if (mouseY >= top && mouseY < top + 32) {
+                boolean overSlot = mouseX >= leftPos + 36 && mouseX < leftPos + 54
+                        && mouseY >= top + 4 && mouseY < top + 22;
+                if (mouseY >= top && mouseY < top + 37 && !overSlot) {
                     allMode = false;
-                    selectedSymbol = null;
+                    selectedCollection = -1;
                     if (minecraft != null && minecraft.gameMode != null) {
-                        minecraft.gameMode.handleInventoryButtonClick(menu.containerId, i);
+                        minecraft.gameMode.handleInventoryButtonClick(menu.containerId, menu.firstVisibleTab() + i);
                     }
                     return true;
                 }
@@ -274,15 +378,63 @@ public final class WritingDeskScreen extends AbstractContainerScreen<WritingDesk
     }
 
     @Override public boolean mouseScrolled(double mouseX, double mouseY, double scrollX, double scrollY) {
-        if (mouseX >= leftPos + 48 && mouseX < leftPos + 203
+        if (mouseX >= leftPos + 58 && mouseX < leftPos + 233
-                && mouseY >= topPos + 18 && mouseY < topPos + 141) {
+                && mouseY >= topPos + 20 && mouseY < topPos + 186) {
-            int rows = ((allMode ? filteredCatalog().size() : pages().size()) + 4) / 5;
+            int rows = (filteredPages().size() + 4) / 5;
-            scrollRows = Math.clamp(scrollRows - (int) Math.signum(scrollY), 0, Math.max(0, rows - 3));
+            scrollRows = Math.clamp(scrollRows - (int) Math.signum(scrollY), 0, Math.max(0, rows - 4));
             return true;
         }
         return super.mouseScrolled(mouseX, mouseY, scrollX, scrollY);
     }
 
+    private void setScrollFromMouse(double mouseY) {
+        int rows = (filteredPages().size() + 4) / 5;
+        int max = Math.max(0, rows - 4);
+        scrollRows = Math.clamp((int) Math.round((mouseY - topPos - 31.5) * max / 143.0), 0, max);
+    }
+
+    @Override public boolean mouseDragged(double mouseX, double mouseY, int button, double dragX, double dragY) {
+        if (button == 0 && pageDragSource != null) {
+            if (Math.abs(mouseX - pageDragStartX) >= 4 || Math.abs(mouseY - pageDragStartY) >= 4)
+                draggingPage = true;
+            return true;
+        }
+        if (button == 0 && draggingScrollbar) {
+            setScrollFromMouse(mouseY);
+            return true;
+        }
+        return super.mouseDragged(mouseX, mouseY, button, dragX, dragY);
+    }
+
+    @Override public boolean mouseReleased(double mouseX, double mouseY, int button) {
+        if (button == 0 && pageDragSource != null) {
+            if (draggingPage) {
+                DisplayPage target = pageAtMouse(mouseX, mouseY);
+                if (target != null && canMovePage(pageDragSource, target)
+                        && minecraft != null && minecraft.gameMode != null) {
+                    selectedCollection = target.collection();
+                    selectedPage = target.index();
+                    minecraft.gameMode.handleInventoryButtonClick(menu.containerId,
+                            WritingDeskMenu.movePageButtonId(pageDragSource.collection(), pageDragSource.index(),
+                                    target.collection(), target.index()));
+                } else if (target == null && minecraft != null && minecraft.gameMode != null) {
+                    int targetSlot = extractTargetSlot(mouseX, mouseY);
+                    minecraft.gameMode.handleInventoryButtonClick(menu.containerId,
+                            WritingDeskMenu.extractPageButtonId(pageDragSource.collection(), pageDragSource.index(),
+                                    targetSlot));
+                }
+            }
+            pageDragSource = null;
+            draggingPage = false;
+            return true;
+        }
+        if (button == 0 && draggingScrollbar) {
+            draggingScrollbar = false;
+            return true;
+        }
+        return super.mouseReleased(mouseX, mouseY, button);
+    }
+
     @Override public boolean keyPressed(int keyCode, int scanCode, int modifiers) {
         if (search != null && search.isFocused()) {
             if (keyCode == 256) {

src/main/java/net/dnorberg/rivencraft/gametest/BookBinderGameTests.java

@@ -0,0 +1,284 @@
+package net.dnorberg.rivencraft.gametest;
+
+import java.util.List;
+import net.dnorberg.rivencraft.Rivencraft;
+import net.dnorberg.rivencraft.block.entity.BookBinderBlockEntity;
+import net.dnorberg.rivencraft.book.AgeReference;
+import net.dnorberg.rivencraft.book.AgeDimensionService;
+import net.dnorberg.rivencraft.book.AgeRegistrySavedData;
+import net.dnorberg.rivencraft.item.PageItem;
+import net.dnorberg.rivencraft.menu.BookBinderMenu;
+import net.dnorberg.rivencraft.registry.ModBlocks;
+import net.dnorberg.rivencraft.registry.ModDataComponents;
+import net.dnorberg.rivencraft.registry.ModItems;
+import net.dnorberg.rivencraft.writing.NotebookContents;
+import net.dnorberg.rivencraft.writing.OrderedWriting;
+import net.dnorberg.rivencraft.writing.SymbolReference;
+import net.dnorberg.rivencraft.writing.WritingEntry;
+import net.minecraft.core.BlockPos;
+import net.minecraft.gametest.framework.GameTest;
+import net.minecraft.gametest.framework.GameTestHelper;
+import net.minecraft.resources.ResourceLocation;
+import net.minecraft.world.entity.item.ItemEntity;
+import net.minecraft.world.inventory.ClickType;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.Items;
+import net.minecraft.world.level.block.Blocks;
+import net.minecraft.world.phys.AABB;
+import net.neoforged.neoforge.gametest.GameTestHolder;
+import net.neoforged.neoforge.gametest.PrefixGameTestTemplate;
+
+@GameTestHolder(Rivencraft.MOD_ID)
+@PrefixGameTestTemplate(false)
+public final class BookBinderGameTests {
+    private BookBinderGameTests() {}
+
+    private static ItemStack terrainPage() {
+        return PageItem.createSymbolPage(new SymbolReference(
+                ResourceLocation.fromNamespaceAndPath(Rivencraft.MOD_ID, "terrain/standard")));
+    }
+
+    private static ItemStack weatherPage() {
+        return PageItem.createSymbolPage(new SymbolReference(
+                ResourceLocation.fromNamespaceAndPath(Rivencraft.MOD_ID, "weather/normal")));
+    }
+
+    private static BookBinderBlockEntity place(GameTestHelper helper) {
+        BlockPos pos = helper.absolutePos(new BlockPos(1, 1, 1));
+        helper.getLevel().setBlock(pos, ModBlocks.BOOK_BINDER.get().defaultBlockState(), 3);
+        return (BookBinderBlockEntity) helper.getLevel().getBlockEntity(pos);
+    }
+
+    @GameTest(template = "empty")
+    public static void binderInputsAndTitleSurviveSaveLoad(GameTestHelper helper) {
+        BookBinderBlockEntity binder = place(helper);
+        binder.setTitle("Ordered Age");
+        binder.setItem(BookBinderBlockEntity.COVER, new ItemStack(Items.LEATHER));
+        binder.setItem(BookBinderBlockEntity.LINK_PANEL, PageItem.createLinkPanelPage());
+        binder.setItem(BookBinderBlockEntity.FIRST_PAGE, terrainPage());
+        var saved = binder.saveWithoutMetadata(helper.getLevel().registryAccess());
+        var restored = new BookBinderBlockEntity(binder.getBlockPos(), binder.getBlockState());
+        restored.loadWithComponents(saved, helper.getLevel().registryAccess());
+        helper.assertValueEqual(restored.title(), "Ordered Age", "Title must persist");
+        helper.assertTrue(restored.getItem(BookBinderBlockEntity.COVER).is(Items.LEATHER), "Cover must persist");
+        helper.assertTrue(restored.getItem(BookBinderBlockEntity.LINK_PANEL).is(ModItems.PAGE.get()),
+                "Link Panel must persist");
+        helper.assertTrue(ItemStack.matches(restored.getItem(BookBinderBlockEntity.FIRST_PAGE), terrainPage()),
+                "Ordered page must persist");
+        helper.assertTrue(restored.canAssemble(), "Restored binder must remain ready to assemble");
+        AgeReference beforeSave = binder.previewBook().get(ModDataComponents.AGE_REFERENCE.get());
+        var previewSaved = binder.saveWithoutMetadata(helper.getLevel().registryAccess());
+        restored.loadWithComponents(previewSaved, helper.getLevel().registryAccess());
+        helper.assertValueEqual(restored.previewBook().get(ModDataComponents.AGE_REFERENCE.get()), beforeSave,
+                "Pending Age identity must survive a world restart");
+        helper.succeed();
+    }
+
+    @GameTest(template = "empty")
+    public static void assemblyIsAtomicAndRetainsPageOrder(GameTestHelper helper) {
+        BookBinderBlockEntity binder = place(helper);
+        binder.setTitle("A New Age");
+        binder.setItem(BookBinderBlockEntity.COVER, new ItemStack(Items.LEATHER));
+        binder.setItem(BookBinderBlockEntity.FIRST_PAGE, terrainPage());
+        binder.setItem(BookBinderBlockEntity.FIRST_PAGE + 1, weatherPage());
+        helper.assertFalse(binder.canAssemble(), "Missing Link Panel must prevent assembly");
+        helper.assertFalse(binder.consumeAssembly(), "Failure must consume nothing");
+        helper.assertTrue(binder.getItem(BookBinderBlockEntity.COVER).is(Items.LEATHER),
+                "Rejected assembly must preserve cover");
+        binder.setItem(BookBinderBlockEntity.LINK_PANEL, PageItem.createLinkPanelPage());
+        var player = helper.makeMockServerPlayerInLevel();
+        player.moveTo(binder.getBlockPos().getX() + 0.5, binder.getBlockPos().getY() + 0.5,
+                binder.getBlockPos().getZ() + 0.5);
+        BookBinderMenu menu = new BookBinderMenu(1, player.getInventory(), binder);
+        menu.broadcastChanges();
+        helper.assertTrue(menu.getSlot(BookBinderMenu.RESULT).hasItem(), "Valid binder must show output");
+        menu.clicked(BookBinderMenu.RESULT, 0, ClickType.PICKUP, player);
+        ItemStack book = menu.getCarried();
+        helper.assertTrue(book.is(ModItems.DESCRIPTIVE_BOOK.get()), "Result must be a Descriptive Book");
+        AgeReference age = book.get(ModDataComponents.AGE_REFERENCE.get());
+        helper.assertTrue(age != null, "Assembled book must already be a written Age book");
+        OrderedWriting writing = book.get(ModDataComponents.BOOK_WRITING.get());
+        helper.assertTrue(writing != null, "Assembled book must keep its writing");
+        helper.assertValueEqual(writing.entries().size(), 3, "Link Panel and two pages must be present");
+        helper.assertValueEqual(writing.entries().get(0).kind(), WritingEntry.Kind.LINK_PANEL,
+                "Link Panel must be first");
+        helper.assertValueEqual(writing.entries().get(1).symbol().orElseThrow().id().toString(),
+                "rivencraft:terrain/standard", "Terrain page order must be preserved");
+        helper.assertValueEqual(writing.entries().get(2).symbol().orElseThrow().id().toString(),
+                "rivencraft:weather/normal", "Weather page order must be preserved");
+        helper.assertTrue(AgeRegistrySavedData.get(helper.getLevel()).find(age.id()).isPresent(),
+                "Taking the completed book must register its random Age definition");
+        helper.assertTrue(binder.getItem(BookBinderBlockEntity.COVER).isEmpty(), "Cover must be consumed once");
+        helper.assertTrue(binder.getItem(BookBinderBlockEntity.LINK_PANEL).isEmpty(), "Link Panel must be consumed once");
+        helper.assertTrue(binder.getItem(BookBinderBlockEntity.FIRST_PAGE).isEmpty(), "Pages must be consumed once");
+        menu.broadcastChanges();
+        helper.assertTrue(menu.getSlot(BookBinderMenu.RESULT).getItem().isEmpty(), "No duplicate output may remain");
+        helper.succeed();
+    }
+
+    @GameTest(template = "empty")
+    public static void linkPanelOnlyCreatesCompletedRandomAgeBook(GameTestHelper helper) {
+        BookBinderBlockEntity binder = place(helper);
+        binder.setTitle("Random Binder Age");
+        binder.setItem(BookBinderBlockEntity.COVER, new ItemStack(Items.LEATHER));
+        binder.setItem(BookBinderBlockEntity.LINK_PANEL, PageItem.createLinkPanelPage());
+        var player = helper.makeMockServerPlayerInLevel();
+        player.moveTo(binder.getBlockPos().getX() + 0.5, binder.getBlockPos().getY() + 0.5,
+                binder.getBlockPos().getZ() + 0.5);
+        BookBinderMenu menu = new BookBinderMenu(1, player.getInventory(), binder);
+        menu.clicked(BookBinderMenu.RESULT, 0, ClickType.PICKUP, player);
+        ItemStack book = menu.getCarried();
+        AgeReference age = book.get(ModDataComponents.AGE_REFERENCE.get());
+        helper.assertTrue(age != null, "Link-Panel-only output must be written, not unwritten");
+        helper.assertValueEqual(age.name(), "Random Binder Age", "The assigned title must name the Age");
+        helper.assertValueEqual(book.get(ModDataComponents.BOOK_WRITING.get()).entries().size(), 1,
+                "A random Age book must contain only its Link Panel when no symbols are supplied");
+        helper.assertTrue(AgeRegistrySavedData.get(helper.getLevel()).find(age.id()).isPresent(),
+                "Taking the book must register its random Age definition");
+        helper.assertTrue(AgeDimensionService.resolve(player, age).isPresent(),
+                "The completed book must resolve to a usable random Age");
+        helper.succeed();
+    }
+
+    @GameTest(template = "empty")
+    public static void notebookImportPreservesOrderAndRejectsOverflow(GameTestHelper helper) {
+        BookBinderBlockEntity binder = place(helper);
+        ItemStack notebook = new ItemStack(ModItems.NOTEBOOK.get());
+        notebook.set(ModDataComponents.NOTEBOOK_CONTENTS.get(), new NotebookContents(List.of(
+                PageItem.createLinkPanelPage(), terrainPage(), weatherPage())));
+        binder.setItem(BookBinderBlockEntity.NOTEBOOK, notebook);
+        helper.assertTrue(binder.importNotebook(), "Notebook pages must import together");
+        helper.assertTrue(binder.getItem(BookBinderBlockEntity.LINK_PANEL).is(ModItems.PAGE.get()),
+                "Imported Link Panel must use its dedicated slot");
+        helper.assertTrue(ItemStack.matches(binder.getItem(BookBinderBlockEntity.FIRST_PAGE), terrainPage()),
+                "First Notebook symbol must stay first");
+        helper.assertTrue(ItemStack.matches(binder.getItem(BookBinderBlockEntity.FIRST_PAGE + 1), weatherPage()),
+                "Second Notebook symbol must stay second");
+        helper.assertValueEqual(binder.getItem(BookBinderBlockEntity.NOTEBOOK)
+                .getOrDefault(ModDataComponents.NOTEBOOK_CONTENTS.get(), NotebookContents.EMPTY).pageCount(), 0,
+                "Empty Notebook cover must remain recoverable");
+        for (int slot = BookBinderBlockEntity.FIRST_PAGE + 2; slot < BookBinderBlockEntity.SIZE; slot++)
+            binder.setItem(slot, terrainPage());
+        ItemStack overflow = new ItemStack(ModItems.NOTEBOOK.get());
+        overflow.set(ModDataComponents.NOTEBOOK_CONTENTS.get(), new NotebookContents(List.of(weatherPage())));
+        binder.setItem(BookBinderBlockEntity.NOTEBOOK, overflow);
+        helper.assertFalse(binder.importNotebook(), "Full binder must reject Notebook import");
+        helper.assertValueEqual(binder.getItem(BookBinderBlockEntity.NOTEBOOK)
+                .getOrDefault(ModDataComponents.NOTEBOOK_CONTENTS.get(), NotebookContents.EMPTY).pageCount(), 1,
+                "Rejected import must preserve the Notebook page");
+        helper.succeed();
+    }
+
+    @GameTest(template = "empty")
+    public static void pageControlsAndBreakingPreserveStoredInputs(GameTestHelper helper) {
+        BookBinderBlockEntity binder = place(helper);
+        binder.setItem(BookBinderBlockEntity.COVER, new ItemStack(Items.LEATHER));
+        binder.setItem(BookBinderBlockEntity.LINK_PANEL, PageItem.createLinkPanelPage());
+        binder.setItem(BookBinderBlockEntity.FIRST_PAGE, terrainPage());
+        var player = helper.makeMockServerPlayerInLevel();
+        player.moveTo(binder.getBlockPos().getX() + 0.5, binder.getBlockPos().getY() + 0.5,
+                binder.getBlockPos().getZ() + 0.5);
+        BookBinderMenu menu = new BookBinderMenu(1, player.getInventory(), binder);
+        helper.assertFalse(menu.clickMenuButton(player, BookBinderMenu.MOVE_PREVIOUS),
+                "Move without selection must be rejected");
+        helper.assertTrue(menu.clickMenuButton(player, BookBinderMenu.SELECT_BASE), "Page selection must succeed");
+        helper.assertTrue(menu.clickMenuButton(player, BookBinderMenu.MOVE_NEXT), "Page move must succeed");
+        helper.assertTrue(binder.getItem(BookBinderBlockEntity.FIRST_PAGE).isEmpty(), "Old position must be empty");
+        helper.assertTrue(ItemStack.matches(binder.getItem(BookBinderBlockEntity.FIRST_PAGE + 1), terrainPage()),
+                "Moved page must keep its data");
+        helper.assertFalse(menu.clickMenuButton(player, 999), "Unknown action must be rejected");
+        BlockPos pos = binder.getBlockPos();
+        helper.getLevel().setBlock(pos, Blocks.AIR.defaultBlockState(), 3);
+        helper.assertFalse(menu.stillValid(player), "Removed binder must invalidate the menu");
+        var drops = helper.getLevel().getEntitiesOfClass(ItemEntity.class, new AABB(pos).inflate(2));
+        int leather = drops.stream().filter(entity -> entity.getItem().is(Items.LEATHER))
+                .mapToInt(entity -> entity.getItem().getCount()).sum();
+        int pages = drops.stream().filter(entity -> entity.getItem().is(ModItems.PAGE.get()))
+                .mapToInt(entity -> entity.getItem().getCount()).sum();
+        helper.assertValueEqual(leather, 1, "Cover must drop once");
+        helper.assertValueEqual(pages, 2, "Link Panel and writing page must drop once each");
+        helper.succeed();
+    }
+
+    @GameTest(template = "empty")
+    public static void fullInventoryCannotConsumeBinderInputs(GameTestHelper helper) {
+        BookBinderBlockEntity binder = place(helper);
+        binder.setTitle("Full Inventory");
+        binder.setItem(BookBinderBlockEntity.COVER, new ItemStack(Items.LEATHER));
+        binder.setItem(BookBinderBlockEntity.LINK_PANEL, PageItem.createLinkPanelPage());
+        var player = helper.makeMockServerPlayerInLevel();
+        player.moveTo(binder.getBlockPos().getX() + 0.5, binder.getBlockPos().getY() + 0.5,
+                binder.getBlockPos().getZ() + 0.5);
+        for (int slot = 0; slot < 36; slot++)
+            player.getInventory().setItem(slot, new ItemStack(Items.COBBLESTONE, 64));
+        BookBinderMenu menu = new BookBinderMenu(1, player.getInventory(), binder);
+        helper.assertTrue(menu.quickMoveStack(player, BookBinderMenu.RESULT).isEmpty(),
+                "Full inventory must reject output transfer");
+        helper.assertTrue(binder.getItem(BookBinderBlockEntity.COVER).is(Items.LEATHER),
+                "Rejected transfer must preserve cover");
+        helper.assertTrue(binder.getItem(BookBinderBlockEntity.LINK_PANEL).is(ModItems.PAGE.get()),
+                "Rejected transfer must preserve Link Panel");
+        helper.assertTrue(menu.getSlot(BookBinderMenu.RESULT).hasItem(),
+                "Result must remain available after inventory space is freed");
+        helper.assertFalse(menu.setTitle(player, "A title that is much too long for the binder slot"),
+                "Oversized title packet must be rejected");
+        helper.assertValueEqual(binder.title(), "Full Inventory", "Rejected title must preserve existing title");
+        helper.succeed();
+    }
+
+    @GameTest(template = "empty")
+    public static void legacyStripInsertsAndRemovesPagesInOrder(GameTestHelper helper) {
+        BookBinderBlockEntity binder = place(helper);
+        var player = helper.makeMockServerPlayerInLevel();
+        player.moveTo(binder.getBlockPos().getX() + 0.5, binder.getBlockPos().getY() + 0.5,
+                binder.getBlockPos().getZ() + 0.5);
+        BookBinderMenu menu = new BookBinderMenu(1, player.getInventory(), binder);
+        menu.setCarried(PageItem.createLinkPanelPage());
+        helper.assertTrue(menu.clickMenuButton(player, BookBinderMenu.STRIP_CLICK_BASE),
+                "The first thumbnail must accept a Link Panel");
+        helper.assertTrue(menu.getCarried().isEmpty(), "Inserted panel must leave the cursor");
+        menu.setCarried(terrainPage());
+        helper.assertTrue(menu.clickMenuButton(player, BookBinderMenu.STRIP_CLICK_BASE + 1),
+                "The strip must accept a written Page");
+        menu.setCarried(weatherPage());
+        helper.assertTrue(menu.clickMenuButton(player, BookBinderMenu.STRIP_CLICK_BASE + 1),
+                "Inserting before a Page must shift it right");
+        helper.assertTrue(ItemStack.matches(binder.getItem(BookBinderBlockEntity.FIRST_PAGE), weatherPage()),
+                "Inserted Page must be first");
+        helper.assertTrue(ItemStack.matches(binder.getItem(BookBinderBlockEntity.FIRST_PAGE + 1), terrainPage()),
+                "Existing Page must move right");
+        helper.assertTrue(menu.clickMenuButton(player, BookBinderMenu.STRIP_CLICK_BASE + 1),
+                "Clicking a thumbnail with an empty cursor must take the Page");
+        helper.assertTrue(ItemStack.matches(menu.getCarried(), weatherPage()),
+                "Removed Page must return to the cursor");
+        helper.assertTrue(ItemStack.matches(binder.getItem(BookBinderBlockEntity.FIRST_PAGE), terrainPage()),
+                "Removal must close the gap");
+        helper.assertFalse(menu.clickMenuButton(player, BookBinderMenu.STRIP_CLICK_BASE),
+                "A symbol Page must not replace the Link Panel");
+        helper.succeed();
+    }
+
+    @GameTest(template = "empty")
+    public static void legacyStripImportsNotebookAtClickedPosition(GameTestHelper helper) {
+        BookBinderBlockEntity binder = place(helper);
+        binder.setItem(BookBinderBlockEntity.LINK_PANEL, PageItem.createLinkPanelPage());
+        binder.setItem(BookBinderBlockEntity.FIRST_PAGE, terrainPage());
+        var player = helper.makeMockServerPlayerInLevel();
+        player.moveTo(binder.getBlockPos().getX() + 0.5, binder.getBlockPos().getY() + 0.5,
+                binder.getBlockPos().getZ() + 0.5);
+        BookBinderMenu menu = new BookBinderMenu(1, player.getInventory(), binder);
+        ItemStack notebook = new ItemStack(ModItems.NOTEBOOK.get());
+        notebook.set(ModDataComponents.NOTEBOOK_CONTENTS.get(), new NotebookContents(List.of(weatherPage())));
+        menu.setCarried(notebook);
+        helper.assertTrue(menu.clickMenuButton(player, BookBinderMenu.STRIP_CLICK_BASE + 1),
+                "Notebook pages must import where clicked");
+        helper.assertValueEqual(menu.getCarried().getOrDefault(
+                ModDataComponents.NOTEBOOK_CONTENTS.get(), NotebookContents.EMPTY).pageCount(), 0,
+                "The empty Notebook must remain on the cursor");
+        helper.assertTrue(ItemStack.matches(binder.getItem(BookBinderBlockEntity.FIRST_PAGE), weatherPage()),
+                "Imported Page must occupy the clicked position");
+        helper.assertTrue(ItemStack.matches(binder.getItem(BookBinderBlockEntity.FIRST_PAGE + 1), terrainPage()),
+                "Existing Page must shift right");
+        helper.succeed();
+    }
+}

src/main/java/net/dnorberg/rivencraft/gametest/WritingDeskGameTests.java

@@ -61,10 +61,10 @@ public final class WritingDeskGameTests {
         helper.getLevel().setBlock(pos, Blocks.AIR.defaultBlockState(), 3);
         var drops = helper.getLevel().getEntitiesOfClass(ItemEntity.class, new AABB(pos).inflate(2));
         int notebooks = drops.stream().filter(e -> e.getItem().is(ModItems.NOTEBOOK.get())).mapToInt(e -> e.getItem().getCount()).sum();
-        int ink = drops.stream().filter(e -> e.getItem().is(ModItems.INK_VIAL.get())).mapToInt(e -> e.getItem().getCount()).sum();
+        int bottles = drops.stream().filter(e -> e.getItem().is(Items.GLASS_BOTTLE)).mapToInt(e -> e.getItem().getCount()).sum();
         int pages = drops.stream().filter(e -> e.getItem().is(Items.PAPER)).mapToInt(e -> e.getItem().getCount()).sum();
         helper.assertValueEqual(notebooks, 1, "Notebook must drop exactly once");
-        helper.assertValueEqual(ink, 1, "Ink must drop exactly once");
+        helper.assertValueEqual(bottles, 1, "Consumed vial must return one glass bottle on break");
         helper.assertValueEqual(pages, 12, "Pages must drop without loss");
         helper.succeed();
     }
@@ -81,7 +81,7 @@ public final class WritingDeskGameTests {
         helper.assertTrue(menu.stillValid(player), "Placed desk must keep its menu valid");
         helper.assertTrue(menu.clickMenuButton(player, 3), "Active collection control must accept a valid tab");
         helper.assertValueEqual(desk.activeCollection(), 3, "Selected tab must be stored on the desk");
-        menu.quickMoveStack(player, 9);
+        menu.quickMoveStack(player, WritingDeskMenu.COPY_RESULT + 1);
         helper.assertValueEqual(desk.getItem(WritingDeskBlockEntity.PAPER).getCount(), 12, "Shift-click must deposit all pages");
         helper.assertTrue(player.getInventory().getItem(9).isEmpty(), "Shift-click must consume player source stack");
         menu.quickMoveStack(player, WritingDeskBlockEntity.PAPER);
@@ -111,12 +111,12 @@ public final class WritingDeskGameTests {
                 "A source page with paper and ink must preview one copy");
         helper.assertValueEqual(desk.getItem(WritingDeskBlockEntity.PAPER).getCount(), 2,
                 "Previewing must not consume paper");
-        helper.assertValueEqual(desk.inkRemaining(), 0, "Previewing must not consume ink");
+        helper.assertValueEqual(desk.inkRemaining(), 16, "Inserting a vial must fill the empty bar before copying");
         menu.clicked(WritingDeskMenu.COPY_RESULT, 0, ClickType.PICKUP, player);
         helper.assertTrue(menu.getCarried().is(ModItems.PAGE.get()), "Taking result must give the copied page");
         helper.assertValueEqual(desk.getItem(WritingDeskBlockEntity.PAPER).getCount(), 1,
                 "Taking a copy must consume one paper");
-        helper.assertValueEqual(desk.inkRemaining(), 15, "First copy must refill to 16 and consume one ink");
+        helper.assertValueEqual(desk.inkRemaining(), 15, "First copy must consume one ink");
         helper.assertTrue(desk.getItem(WritingDeskBlockEntity.INK).isEmpty(), "Refill must consume one vial");
         helper.assertTrue(desk.getItem(WritingDeskBlockEntity.RETURN).is(Items.GLASS_BOTTLE),
                 "Refill must return a vanilla glass bottle");
@@ -135,6 +135,48 @@ public final class WritingDeskGameTests {
         helper.succeed();
     }
 
+    @GameTest(template = "empty")
+    public static void emptyDeskInkBarRefillsWithoutCopying(GameTestHelper helper) {
+        BlockPos pos = helper.absolutePos(new BlockPos(1, 1, 1));
+        helper.getLevel().setBlock(pos, ModBlocks.WRITING_DESK.get().defaultBlockState(), 3);
+        WritingDeskBlockEntity desk = (WritingDeskBlockEntity) helper.getLevel().getBlockEntity(pos);
+        desk.setItem(WritingDeskBlockEntity.INK, new ItemStack(ModItems.INK_VIAL.get(), 2));
+        helper.assertValueEqual(desk.inkRemaining(), 16, "Inserting a vial must refill immediately");
+        helper.assertValueEqual(desk.getItem(WritingDeskBlockEntity.INK).getCount(), 1,
+                "Refill must consume exactly one vial");
+        helper.assertTrue(desk.getItem(WritingDeskBlockEntity.RETURN).is(Items.GLASS_BOTTLE),
+                "Refill must put a vanilla glass bottle in the return slot");
+        helper.runAfterDelay(2, () -> {
+            helper.assertValueEqual(desk.inkRemaining(), 16, "Full bar must not refill again");
+            helper.assertValueEqual(desk.getItem(WritingDeskBlockEntity.INK).getCount(), 1,
+                    "Full bar must leave the second vial untouched");
+            helper.assertValueEqual(desk.getItem(WritingDeskBlockEntity.RETURN).getCount(), 1,
+                    "Full bar must not create another bottle");
+            helper.succeed();
+        });
+    }
+
+    @GameTest(template = "empty")
+    public static void emptyDeskInkBarWaitsForBottleSpace(GameTestHelper helper) {
+        BlockPos pos = helper.absolutePos(new BlockPos(1, 1, 1));
+        helper.getLevel().setBlock(pos, ModBlocks.WRITING_DESK.get().defaultBlockState(), 3);
+        WritingDeskBlockEntity desk = (WritingDeskBlockEntity) helper.getLevel().getBlockEntity(pos);
+        desk.setItem(WritingDeskBlockEntity.RETURN, new ItemStack(Items.GLASS_BOTTLE, 64));
+        desk.setItem(WritingDeskBlockEntity.INK, new ItemStack(ModItems.INK_VIAL.get()));
+        helper.assertValueEqual(desk.inkRemaining(), 0, "Full bottle slot must block automatic refill");
+        helper.assertTrue(desk.getItem(WritingDeskBlockEntity.INK).is(ModItems.INK_VIAL.get()),
+                "Blocked refill must preserve the vial");
+        helper.assertValueEqual(desk.getItem(WritingDeskBlockEntity.RETURN).getCount(), 64,
+                "Blocked refill must preserve the bottle stack");
+        desk.removeItem(WritingDeskBlockEntity.RETURN, 1);
+        helper.assertValueEqual(desk.inkRemaining(), 16, "Removing a bottle must immediately permit refill");
+        helper.assertTrue(desk.getItem(WritingDeskBlockEntity.INK).isEmpty(),
+                "Refill must consume the waiting vial");
+        helper.assertValueEqual(desk.getItem(WritingDeskBlockEntity.RETURN).getCount(), 64,
+                "Refill must return one glass bottle to the available space");
+        helper.succeed();
+    }
+
     @GameTest(template = "empty")
     public static void shiftClickCopiesOnlyWhenResourcesAndBottleSpaceExist(GameTestHelper helper) {
         BlockPos pos = helper.absolutePos(new BlockPos(1, 1, 1));
@@ -142,8 +184,8 @@ public final class WritingDeskGameTests {
         WritingDeskBlockEntity desk = (WritingDeskBlockEntity) helper.getLevel().getBlockEntity(pos);
         desk.setItem(0, PageItem.createLinkPanelPage());
         desk.setItem(WritingDeskBlockEntity.PAPER, new ItemStack(Items.PAPER, 2));
-        desk.setItem(WritingDeskBlockEntity.INK, new ItemStack(ModItems.INK_VIAL.get()));
         desk.setItem(WritingDeskBlockEntity.RETURN, new ItemStack(Items.GLASS_BOTTLE, 64));
+        desk.setItem(WritingDeskBlockEntity.INK, new ItemStack(ModItems.INK_VIAL.get()));
         var player = helper.makeMockServerPlayerInLevel();
         player.moveTo(pos.getX() + 0.5, pos.getY() + 0.5, pos.getZ() + 0.5);
         WritingDeskMenu menu = new WritingDeskMenu(1, player.getInventory(), desk);
@@ -180,7 +222,7 @@ public final class WritingDeskGameTests {
         menu.broadcastChanges();
         helper.assertTrue(menu.getSlot(WritingDeskMenu.COPY_RESULT).getItem().isEmpty(),
                 "An empty selected position must not create a copy");
-        helper.assertTrue(menu.clickMenuButton(player, 17), "Second page selection must be accepted");
+        helper.assertTrue(menu.clickMenuButton(player, WritingDeskMenu.PAGE_BUTTON_BASE + 1), "Second page selection must be accepted");
         menu.broadcastChanges();
         helper.assertTrue(menu.getSlot(WritingDeskMenu.COPY_RESULT).getItem().is(ModItems.PAGE.get()),
                 "Selecting the populated page must show a copy");
@@ -230,8 +272,8 @@ public final class WritingDeskGameTests {
         var player = helper.makeMockServerPlayerInLevel();
         player.moveTo(pos.getX() + 0.5, pos.getY() + 0.5, pos.getZ() + 0.5);
         WritingDeskMenu menu = new WritingDeskMenu(1, player.getInventory(), desk);
-        helper.assertFalse(menu.clickMenuButton(player, 101), "Out-of-range catalog index must be rejected");
+        helper.assertFalse(menu.clickMenuButton(player, WritingDeskMenu.CATALOG_BUTTON_BASE + 1), "Out-of-range catalog index must be rejected");
-        helper.assertTrue(menu.clickMenuButton(player, 100), "Known catalog symbol must be selectable");
+        helper.assertTrue(menu.clickMenuButton(player, WritingDeskMenu.CATALOG_BUTTON_BASE), "Known catalog symbol must be selectable");
         desk.setItem(WritingDeskBlockEntity.PAPER, new ItemStack(Items.PAPER));
         desk.setItem(WritingDeskBlockEntity.INK, new ItemStack(ModItems.INK_VIAL.get()));
         menu.broadcastChanges();
@@ -262,9 +304,9 @@ public final class WritingDeskGameTests {
                 "Full inventory must reject shift-click copy");
         helper.assertValueEqual(desk.getItem(WritingDeskBlockEntity.PAPER).getCount(), 1,
                 "Rejected copy must preserve paper");
-        helper.assertValueEqual(desk.inkRemaining(), 0, "Rejected copy must preserve ink meter");
+        helper.assertValueEqual(desk.inkRemaining(), 16, "Rejected copy must preserve the filled ink meter");
-        helper.assertTrue(desk.getItem(WritingDeskBlockEntity.INK).is(ModItems.INK_VIAL.get()),
+        helper.assertTrue(desk.getItem(WritingDeskBlockEntity.INK).isEmpty(),
-                "Rejected copy must preserve ink vial");
+                "The vial should already have refilled the empty meter");
         helper.succeed();
     }
 
@@ -321,4 +363,260 @@ public final class WritingDeskGameTests {
                 "Open shelves must not cull terrain behind the desk");
         helper.succeed();
     }
+
+    @GameTest(template = "empty")
+    public static void allPagesSelectionUsesTheRequestedPhysicalTab(GameTestHelper helper) {
+        BlockPos pos = helper.absolutePos(new BlockPos(1, 1, 1));
+        helper.getLevel().setBlock(pos, ModBlocks.WRITING_DESK.get().defaultBlockState(), 3);
+        WritingDeskBlockEntity desk = (WritingDeskBlockEntity) helper.getLevel().getBlockEntity(pos);
+        ItemStack first = PageItem.createLinkPanelPage();
+        ItemStack second = PageItem.createSymbolPage(new SymbolReference(
+                ResourceLocation.parse("rivencraft:terrain/standard")));
+        desk.setItem(0, first);
+        ItemStack notebook = new ItemStack(ModItems.NOTEBOOK.get());
+        notebook.set(ModDataComponents.NOTEBOOK_CONTENTS.get(),
+                new NotebookContents(List.of(ItemStack.EMPTY, second)));
+        desk.setItem(1, notebook);
+        desk.setItem(WritingDeskBlockEntity.PAPER, new ItemStack(Items.PAPER));
+        desk.setItem(WritingDeskBlockEntity.INK, new ItemStack(ModItems.INK_VIAL.get()));
+        var player = helper.makeMockServerPlayerInLevel();
+        player.moveTo(pos.getX() + 0.5, pos.getY() + 0.5, pos.getZ() + 0.5);
+        WritingDeskMenu menu = new WritingDeskMenu(1, player.getInventory(), desk);
+        helper.assertFalse(menu.clickMenuButton(player, WritingDeskMenu.ALL_PAGE_BUTTON_BASE + 2 * NotebookContents.MAX_PAGES),
+                "ALL view must reject empty cross-tab positions");
+        helper.assertTrue(menu.clickMenuButton(player, WritingDeskMenu.ALL_PAGE_BUTTON_BASE + NotebookContents.MAX_PAGES + 1),
+                "ALL view must accept the populated second tab page");
+        helper.assertTrue(ItemStack.matches(menu.getSlot(WritingDeskMenu.COPY_RESULT).getItem(), second),
+                "Copy preview must match the physical page selected from the other tab");
+        helper.assertValueEqual(desk.activeCollection(), 0,
+                "Selecting from ALL must not silently change the active tab");
+        helper.succeed();
+    }
+
+    @GameTest(template = "empty")
+    public static void tabGroupsCycleByFourAndProtectHiddenSlots(GameTestHelper helper) {
+        BlockPos pos = helper.absolutePos(new BlockPos(1, 1, 1));
+        helper.getLevel().setBlock(pos, ModBlocks.WRITING_DESK.get().defaultBlockState(), 3);
+        var desk = (WritingDeskBlockEntity) helper.getLevel().getBlockEntity(pos);
+        var player = helper.makeMockServerPlayerInLevel();
+        player.moveTo(pos.getX() + 0.5, pos.getY() + 0.5, pos.getZ() + 0.5);
+        var menu = new WritingDeskMenu(1, player.getInventory(), desk);
+        var otherViewer = new WritingDeskMenu(2, player.getInventory(), desk);
+        menu.clickMenuButton(player, WritingDeskMenu.PREVIOUS_TABS);
+        helper.assertValueEqual(menu.firstVisibleTab(), 0, "Previous must stop at tabs 1-4");
+        menu.clickMenuButton(player, WritingDeskMenu.NEXT_TABS);
+        helper.assertValueEqual(menu.firstVisibleTab(), 4, "Next must show tabs 5-8");
+        helper.assertValueEqual(otherViewer.firstVisibleTab(), 0, "Cycling must not move another viewer's slots");
+        helper.assertFalse(menu.getSlot(0).isActive(), "Earlier tab slots must be hidden");
+        helper.assertTrue(menu.getSlot(4).isActive(), "New group's slots must be interactive");
+        desk.setItem(0, new ItemStack(ModItems.NOTEBOOK.get()));
+        menu.clicked(0, 0, ClickType.PICKUP, player);
+        helper.assertTrue(menu.getCarried().isEmpty(), "Hidden slot clicks must not take items");
+        helper.assertTrue(menu.quickMoveStack(player, 0).isEmpty(), "Hidden shift-click must be rejected");
+        player.getInventory().setItem(9, new ItemStack(ModItems.NOTEBOOK.get()));
+        menu.quickMoveStack(player, WritingDeskMenu.COPY_RESULT + 1);
+        helper.assertTrue(desk.getItem(4).is(ModItems.NOTEBOOK.get()), "Shift-click must use the visible group");
+        for (int i = 0; i < 30; i++) menu.clickMenuButton(player, WritingDeskMenu.NEXT_TABS);
+        helper.assertValueEqual(menu.firstVisibleTab(), 84, "Last group must be tabs 85-88");
+        helper.assertTrue(menu.clickMenuButton(player, 87), "Tab 88 must be selectable without page-ID collisions");
+        helper.assertValueEqual(desk.activeCollection(), 87, "Tab 88 must become active");
+        helper.assertFalse(menu.clickMenuButton(player, 88), "Tab 89 must not exist");
+        desk.setItem(87, PageItem.createLinkPanelPage());
+        desk.setItem(WritingDeskBlockEntity.PAPER, new ItemStack(Items.PAPER));
+        desk.setItem(WritingDeskBlockEntity.INK, new ItemStack(ModItems.INK_VIAL.get()));
+        helper.assertTrue(menu.clickMenuButton(player, WritingDeskMenu.ALL_PAGE_BUTTON_BASE + 87 * NotebookContents.MAX_PAGES),
+                "ALL must select a physical page from tab 88");
+        helper.assertTrue(menu.quickMoveStack(player, WritingDeskMenu.COPY_RESULT).is(ModItems.PAGE.get()),
+                "Tab 88's page must be copyable");
+        menu.clickMenuButton(player, WritingDeskMenu.PREVIOUS_TABS);
+        helper.assertValueEqual(menu.firstVisibleTab(), 80, "Previous must move back four tabs");
+        helper.succeed();
+    }
+
+    @GameTest(template = "empty")
+    public static void oldDeskInventoryMigratesAndAll88TabsPersist(GameTestHelper helper) {
+        BlockPos pos = helper.absolutePos(new BlockPos(1, 1, 1));
+        var registries = helper.getLevel().registryAccess();
+        var oldItems = net.minecraft.core.NonNullList.withSize(8, ItemStack.EMPTY);
+        oldItems.set(0, new ItemStack(ModItems.NOTEBOOK.get()));
+        oldItems.set(3, PageItem.createLinkPanelPage());
+        oldItems.set(4, new ItemStack(ModItems.INK_VIAL.get(), 2));
+        oldItems.set(5, new ItemStack(Items.GLASS_BOTTLE, 3));
+        oldItems.set(6, new ItemStack(Items.PAPER, 12));
+        oldItems.set(7, PageItem.createLinkPanelPage());
+        var oldTag = new net.minecraft.nbt.CompoundTag();
+        net.minecraft.world.ContainerHelper.saveAllItems(oldTag, oldItems, registries);
+        oldTag.putInt("InkRemaining", 7);
+        oldTag.putInt("ActiveCollection", 3);
+        var desk = new WritingDeskBlockEntity(pos, ModBlocks.WRITING_DESK.get().defaultBlockState());
+        desk.loadWithComponents(oldTag, registries);
+        for (int i = 0; i < 4; i++) {
+            helper.assertTrue(ItemStack.matches(desk.getItem(i), oldItems.get(i)), "Original tab must survive migration");
+            helper.assertTrue(ItemStack.matches(desk.getItem(WritingDeskBlockEntity.INK + i), oldItems.get(4 + i)),
+                    "Original supplies and legacy output must survive migration");
+            helper.assertTrue(desk.getItem(4 + i).isEmpty(), "Supplies must not be duplicated into new tabs");
+        }
+        helper.assertValueEqual(desk.inkRemaining(), 7, "Migration must preserve ink meter");
+        helper.assertValueEqual(desk.activeCollection(), 3, "Migration must preserve active tab");
+        for (int i = 0; i < WritingDeskBlockEntity.COLLECTIONS; i++) desk.setItem(i, PageItem.createLinkPanelPage());
+        desk.setActiveCollection(87);
+        var restored = new WritingDeskBlockEntity(pos, ModBlocks.WRITING_DESK.get().defaultBlockState());
+        restored.loadWithComponents(desk.saveWithoutMetadata(registries), registries);
+        for (int i = 0; i < WritingDeskBlockEntity.COLLECTIONS; i++)
+            helper.assertTrue(restored.getItem(i).is(ModItems.PAGE.get()), "All 88 tab contents must survive save/load");
+        helper.assertValueEqual(restored.activeCollection(), 87, "Tab 88 selection must survive save/load");
+        helper.assertValueEqual(restored.getItem(WritingDeskBlockEntity.PAPER).getCount(), 12, "Reload must not repeat migration");
+        helper.succeed();
+    }
+
+    @GameTest(template = "empty")
+    public static void surfacePlacesCarriedPagesWithoutLossOrOverwrite(GameTestHelper helper) {
+        BlockPos pos = helper.absolutePos(new BlockPos(1, 1, 1));
+        helper.getLevel().setBlock(pos, ModBlocks.WRITING_DESK.get().defaultBlockState(), 3);
+        var desk = (WritingDeskBlockEntity) helper.getLevel().getBlockEntity(pos);
+        desk.setItem(87, new ItemStack(ModItems.NOTEBOOK.get()));
+        var player = helper.makeMockServerPlayerInLevel();
+        player.moveTo(pos.getX() + 0.5, pos.getY() + 0.5, pos.getZ() + 0.5);
+        var menu = new WritingDeskMenu(1, player.getInventory(), desk);
+        ItemStack held = PageItem.createLinkPanelPage().copyWithCount(3);
+        ItemStack expectedPage = held.copyWithCount(1);
+        player.getInventory().setItem(9, held);
+        menu.clicked(WritingDeskMenu.COPY_RESULT + 1, 0, ClickType.PICKUP, player);
+        int lastPosition = WritingDeskMenu.PLACE_PAGE_BUTTON_BASE + 87 * NotebookContents.MAX_PAGES + 26;
+        helper.assertTrue(menu.clickMenuButton(player, lastPosition), "Surface must place into final notebook position");
+        helper.assertValueEqual(menu.getCarried().getCount(), 2, "Placing must consume exactly one held page");
+        var pages = desk.getItem(87).get(ModDataComponents.NOTEBOOK_CONTENTS.get()).pages();
+        helper.assertValueEqual(pages.size(), 27, "Placement must preserve addressed position");
+        helper.assertTrue(pages.get(0).isEmpty() && pages.get(25).isEmpty(), "Placement must preserve preceding gaps");
+        helper.assertTrue(ItemStack.matches(pages.get(26), expectedPage), "Stored page must preserve components");
+        helper.assertFalse(menu.clickMenuButton(player, lastPosition), "Occupied position must not be overwritten");
+        helper.assertValueEqual(menu.getCarried().getCount(), 2, "Rejected placement must preserve cursor");
+        helper.assertFalse(menu.clickMenuButton(player, WritingDeskMenu.PLACE_PAGE_BUTTON_BASE + 88 * NotebookContents.MAX_PAGES),
+                "Out-of-range placement must be rejected");
+        helper.assertValueEqual(menu.pageCapacity(87), NotebookContents.MAX_PAGES, "Notebook tab must expose normal notebook capacity");
+        helper.assertValueEqual(menu.pageCapacity(0), 0, "Empty tab has no page storage");
+        helper.assertFalse(menu.clickMenuButton(player, WritingDeskMenu.PLACE_PAGE_BUTTON_BASE), "Empty tab must require a collection first");
+        desk.setItem(0, PageItem.createLinkPanelPage());
+        helper.assertValueEqual(menu.pageCapacity(0), 1, "Loose page tab must expose exactly one position");
+        helper.assertFalse(menu.clickMenuButton(player, WritingDeskMenu.PLACE_PAGE_BUTTON_BASE), "Loose page must not be replaced");
+        helper.assertFalse(menu.clickMenuButton(player, WritingDeskMenu.PLACE_PAGE_BUTTON_BASE + 1), "Loose page tab must not grow extra positions");
+        helper.assertValueEqual(menu.getCarried().getCount(), 2, "Rejected placements must preserve cursor");
+        helper.assertTrue(menu.clickMenuButton(player, lastPosition - 1), "A second empty notebook position must accept a page");
+        helper.assertTrue(menu.clickMenuButton(player, lastPosition - 2), "A third empty notebook position must accept the last page");
+        helper.assertTrue(menu.getCarried().isEmpty(), "Final placement must clear cursor");
+        menu.setCarried(new ItemStack(Items.DIAMOND));
+        helper.assertFalse(menu.clickMenuButton(player, lastPosition - 3), "Non-page items must be rejected");
+        helper.assertTrue(menu.getCarried().is(Items.DIAMOND), "Rejected item must remain held");
+        var restored = new WritingDeskBlockEntity(pos, ModBlocks.WRITING_DESK.get().defaultBlockState());
+        restored.loadWithComponents(desk.saveWithoutMetadata(helper.getLevel().registryAccess()), helper.getLevel().registryAccess());
+        helper.assertValueEqual(restored.getItem(87).get(ModDataComponents.NOTEBOOK_CONTENTS.get()).pageCount(), 3,
+                "Placed pages must persist in the notebook");
+        helper.succeed();
+    }
+
+    @GameTest(template = "empty")
+    public static void deskSurfaceDragMovesAndSwapsNotebookPages(GameTestHelper helper) {
+        BlockPos pos = helper.absolutePos(new BlockPos(1, 1, 1));
+        helper.getLevel().setBlock(pos, ModBlocks.WRITING_DESK.get().defaultBlockState(), 3);
+        var desk = (WritingDeskBlockEntity) helper.getLevel().getBlockEntity(pos);
+        ItemStack linkPanel = PageItem.createLinkPanelPage();
+        ItemStack terrain = PageItem.createSymbolPage(new SymbolReference(
+                ResourceLocation.parse("rivencraft:terrain/standard")));
+        ItemStack firstBook = new ItemStack(ModItems.NOTEBOOK.get());
+        firstBook.set(ModDataComponents.NOTEBOOK_CONTENTS.get(), new NotebookContents(List.of(linkPanel, terrain)));
+        desk.setItem(0, firstBook);
+        desk.setItem(1, new ItemStack(ModItems.NOTEBOOK.get()));
+        desk.setItem(2, PageItem.createLinkPanelPage());
+        var player = helper.makeMockServerPlayerInLevel();
+        player.moveTo(pos.getX() + 0.5, pos.getY() + 0.5, pos.getZ() + 0.5);
+        var menu = new WritingDeskMenu(1, player.getInventory(), desk);
+        int moveToEmpty = WritingDeskMenu.movePageButtonId(0, 0, 0, 26);
+        helper.assertTrue(menu.clickMenuButton(player, moveToEmpty), "Drag must move to a distant empty notebook position");
+        var pages = desk.getItem(0).get(ModDataComponents.NOTEBOOK_CONTENTS.get()).pages();
+        helper.assertTrue(pages.get(0).isEmpty(), "Moving must clear the source position");
+        helper.assertTrue(ItemStack.matches(pages.get(26), linkPanel), "Moving must preserve page components");
+        helper.assertValueEqual(desk.getItem(0).get(ModDataComponents.NOTEBOOK_CONTENTS.get()).pageCount(), 2,
+                "Moving must preserve total page count");
+        helper.assertTrue(menu.clickMenuButton(player, WritingDeskMenu.movePageButtonId(0, 26, 0, 1)),
+                "Drag onto an occupied position must swap pages");
+        pages = desk.getItem(0).get(ModDataComponents.NOTEBOOK_CONTENTS.get()).pages();
+        helper.assertTrue(ItemStack.matches(pages.get(1), linkPanel) && ItemStack.matches(pages.get(26), terrain),
+                "Swap must preserve both pages");
+        helper.assertTrue(menu.clickMenuButton(player, WritingDeskMenu.movePageButtonId(0, 1, 1, 5)),
+                "Drag into another notebook must work");
+        var otherPages = desk.getItem(1).get(ModDataComponents.NOTEBOOK_CONTENTS.get()).pages();
+        helper.assertTrue(ItemStack.matches(otherPages.get(5), linkPanel)
+                && desk.getItem(0).get(ModDataComponents.NOTEBOOK_CONTENTS.get()).pages().get(1).isEmpty(),
+                "Cross notebook move must have one destination and no old source");
+        helper.assertFalse(menu.clickMenuButton(player, WritingDeskMenu.movePageButtonId(0, 1, 1, 6)),
+                "Dragging an empty source must be rejected");
+        helper.assertTrue(menu.clickMenuButton(player, WritingDeskMenu.movePageButtonId(2, 0, 1, 6)),
+                "A loose page should move into a notebook position");
+        helper.assertTrue(desk.getItem(2).isEmpty()
+                && desk.getItem(1).get(ModDataComponents.NOTEBOOK_CONTENTS.get()).pages().get(6).is(ModItems.PAGE.get()),
+                "Moving a loose page must empty its tab without losing the item");
+        helper.assertFalse(menu.clickMenuButton(player, WritingDeskMenu.movePageButtonId(1, 5, 1, 5)),
+                "A no-op drag must be rejected");
+        menu.setCarried(new ItemStack(Items.DIAMOND));
+        helper.assertFalse(menu.clickMenuButton(player, WritingDeskMenu.movePageButtonId(1, 5, 1, 6)),
+                "Held inventory items must not be moved by a panel drag");
+        helper.assertTrue(ItemStack.matches(desk.getItem(1).get(ModDataComponents.NOTEBOOK_CONTENTS.get()).pages().get(5), linkPanel),
+                "Rejected drags must leave notebook data intact");
+        helper.succeed();
+    }
+
+    @GameTest(template = "empty")
+    public static void deskSurfaceDragExtractsPagesToInventoryAndTabs(GameTestHelper helper) {
+        BlockPos pos = helper.absolutePos(new BlockPos(1, 1, 1));
+        helper.getLevel().setBlock(pos, ModBlocks.WRITING_DESK.get().defaultBlockState(), 3);
+        var desk = (WritingDeskBlockEntity) helper.getLevel().getBlockEntity(pos);
+        ItemStack page = PageItem.createLinkPanelPage();
+        ItemStack source = new ItemStack(ModItems.NOTEBOOK.get());
+        source.set(ModDataComponents.NOTEBOOK_CONTENTS.get(),
+                new NotebookContents(List.of(page, page, page, page, page, page)));
+        desk.setItem(0, source);
+        ItemStack otherBook = new ItemStack(ModItems.NOTEBOOK.get());
+        ItemStack terrain = PageItem.createSymbolPage(new SymbolReference(
+                ResourceLocation.parse("rivencraft:terrain/standard")));
+        otherBook.set(ModDataComponents.NOTEBOOK_CONTENTS.get(), new NotebookContents(List.of(terrain)));
+        desk.setItem(2, otherBook);
+        var player = helper.makeMockServerPlayerInLevel();
+        player.moveTo(pos.getX() + 0.5, pos.getY() + 0.5, pos.getZ() + 0.5);
+        player.getInventory().setItem(10, page.copyWithCount(2));
+        var menu = new WritingDeskMenu(1, player.getInventory(), desk);
+        int inventoryStart = WritingDeskMenu.COPY_RESULT + 1;
+
+        helper.assertTrue(menu.clickMenuButton(player, WritingDeskMenu.extractPageButtonId(0, 0, -1)),
+                "Dropping away from a slot must return the page to the cursor");
+        helper.assertTrue(ItemStack.matches(menu.getCarried(), page), "Cursor must hold the original page item");
+        helper.assertFalse(menu.clickMenuButton(player, WritingDeskMenu.extractPageButtonId(0, 1, inventoryStart)),
+                "Extraction must not replace an occupied cursor");
+        menu.setCarried(ItemStack.EMPTY);
+        helper.assertTrue(menu.clickMenuButton(player, WritingDeskMenu.extractPageButtonId(0, 1, inventoryStart)),
+                "Dropping on player inventory must transfer a page");
+        helper.assertTrue(ItemStack.matches(player.getInventory().getItem(9), page),
+                "Transferred page must retain its components");
+        helper.assertTrue(menu.clickMenuButton(player, WritingDeskMenu.extractPageButtonId(0, 2, 1)),
+                "Dropping on an empty tab must store a loose page");
+        helper.assertTrue(ItemStack.matches(desk.getItem(1), page), "Tab must hold the extracted page");
+        helper.assertTrue(menu.clickMenuButton(player, WritingDeskMenu.extractPageButtonId(0, 3, 2)),
+                "Dropping on a notebook tab must insert the page");
+        var otherPages = desk.getItem(2).get(ModDataComponents.NOTEBOOK_CONTENTS.get()).pages();
+        helper.assertTrue(ItemStack.matches(otherPages.get(0), terrain)
+                && ItemStack.matches(otherPages.get(1), page), "Notebook drop must preserve existing pages");
+        helper.assertTrue(menu.clickMenuButton(player, WritingDeskMenu.extractPageButtonId(0, 4, inventoryStart + 1)),
+                "Dropping on a matching inventory stack must merge one page");
+        helper.assertValueEqual(player.getInventory().getItem(10).getCount(), 3, "Merge must add exactly one page");
+        helper.assertFalse(menu.clickMenuButton(player, WritingDeskMenu.extractPageButtonId(0, 5, 1)),
+                "Occupied loose-page tabs must reject a drop");
+        helper.assertFalse(menu.clickMenuButton(player, WritingDeskMenu.extractPageButtonId(0, 5, WritingDeskBlockEntity.INK)),
+                "Ink slot must not accept an extracted page");
+        helper.assertValueEqual(desk.getItem(0).get(ModDataComponents.NOTEBOOK_CONTENTS.get()).pageCount(), 1,
+                "Rejected drops must leave the remaining source page in the notebook");
+        helper.assertTrue(menu.clickMenuButton(player, WritingDeskMenu.extractPageButtonId(1, 0, -1)),
+                "A loose page shown on the panel must be draggable back to the cursor");
+        helper.assertTrue(desk.getItem(1).isEmpty() && ItemStack.matches(menu.getCarried(), page),
+                "Extracting a loose page must empty its tab and return the same item");
+        helper.succeed();
+    }
 }

src/main/java/net/dnorberg/rivencraft/menu/BookBinderMenu.java

@@ -0,0 +1,224 @@
+package net.dnorberg.rivencraft.menu;
+
+import net.dnorberg.rivencraft.block.entity.BookBinderBlockEntity;
+import net.dnorberg.rivencraft.item.PageItem;
+import net.dnorberg.rivencraft.registry.ModItems;
+import net.dnorberg.rivencraft.registry.ModMenus;
+import net.dnorberg.rivencraft.writing.PageContent;
+import net.minecraft.network.RegistryFriendlyByteBuf;
+import net.minecraft.world.Container;
+import net.minecraft.world.SimpleContainer;
+import net.minecraft.world.entity.player.Inventory;
+import net.minecraft.world.entity.player.Player;
+import net.minecraft.world.inventory.AbstractContainerMenu;
+import net.minecraft.world.inventory.ClickType;
+import net.minecraft.world.inventory.DataSlot;
+import net.minecraft.world.inventory.Slot;
+import net.minecraft.world.item.ItemStack;
+import net.minecraft.world.item.Items;
+
+/** Fixed, ordered binder slots and a server-owned virtual result. */
+public final class BookBinderMenu extends AbstractContainerMenu {
+    public static final int RESULT = BookBinderBlockEntity.SIZE;
+    public static final int SELECT_BASE = 100;
+    public static final int MOVE_PREVIOUS = 200;
+    public static final int MOVE_NEXT = 201;
+    public static final int IMPORT_NOTEBOOK = 202;
+    public static final int STRIP_CLICK_BASE = 300;
+    private static final int PLAYER_START = RESULT + 1;
+
+    private final BookBinderBlockEntity binder;
+    private final Container inputs;
+    private final SimpleContainer result = new SimpleContainer(1);
+    private final boolean clientSide;
+    private int selectedPage = -1;
+
+    public BookBinderMenu(int id, Inventory inventory, RegistryFriendlyByteBuf data) {
+        this(id, inventory, inventory.player.level().getBlockEntity(data.readBlockPos())
+                instanceof BookBinderBlockEntity found ? found : null);
+    }
+
+    public BookBinderMenu(int id, Inventory inventory, BookBinderBlockEntity binder) {
+        super(ModMenus.BOOK_BINDER.get(), id);
+        this.binder = binder;
+        inputs = binder == null ? new SimpleContainer(BookBinderBlockEntity.SIZE) : binder;
+        clientSide = inventory.player.level().isClientSide;
+        addDataSlot(new DataSlot() {
+            @Override public int get() { return selectedPage; }
+            @Override public void set(int value) { selectedPage = value; }
+        });
+        addSlot(new BinderSlot(BookBinderBlockEntity.COVER, 8, 27, 64));
+        addSlot(new BinderSlot(BookBinderBlockEntity.LINK_PANEL, -1000, -1000, 1));
+        addSlot(new BinderSlot(BookBinderBlockEntity.NOTEBOOK, -1000, -1000, 1));
+        for (int page = 0; page < BookBinderBlockEntity.PAGE_COUNT; page++) {
+            addSlot(new BinderSlot(BookBinderBlockEntity.FIRST_PAGE + page, -1000, -1000, 1));
+        }
+        addSlot(new ResultSlot(result, 0, 152, 27));
+        for (int row = 0; row < 3; row++) {
+            for (int column = 0; column < 9; column++) {
+                addSlot(new Slot(inventory, column + row * 9 + 9, 8 + column * 18, 99 + row * 18));
+            }
+        }
+        for (int column = 0; column < 9; column++) {
+            addSlot(new Slot(inventory, column, 8 + column * 18, 157));
+        }
+        refreshResult();
+    }
+
+    public int selectedPage() { return selectedPage; }
+    public String title() { return binder == null ? "" : binder.title(); }
+    public boolean setTitle(Player player, String title) {
+        if (clientSide || !stillValid(player) || title == null
+                || title.length() > BookBinderBlockEntity.MAX_TITLE_LENGTH) return false;
+        binder.setTitle(title);
+        refreshResult();
+        broadcastChanges();
+        return true;
+    }
+
+    @Override public boolean stillValid(Player player) {
+        return binder != null && binder.stillValid(player);
+    }
+
+    @Override public boolean clickMenuButton(Player player, int id) {
+        if (clientSide || !stillValid(player)) return false;
+        if (id >= STRIP_CLICK_BASE && id <= STRIP_CLICK_BASE + BookBinderBlockEntity.PAGE_COUNT) {
+            if (!clickStrip(id - STRIP_CLICK_BASE)) return false;
+        } else if (id >= SELECT_BASE && id < SELECT_BASE + BookBinderBlockEntity.PAGE_COUNT) {
+            selectedPage = id - SELECT_BASE;
+        } else if (id == MOVE_PREVIOUS || id == MOVE_NEXT) {
+            int target = selectedPage + (id == MOVE_PREVIOUS ? -1 : 1);
+            if (selectedPage < 0 || target < 0 || target >= BookBinderBlockEntity.PAGE_COUNT
+                    || binder.getItem(BookBinderBlockEntity.FIRST_PAGE + selectedPage).isEmpty()
+                    || !getCarried().isEmpty()) return false;
+            int fromSlot = BookBinderBlockEntity.FIRST_PAGE + selectedPage;
+            int toSlot = BookBinderBlockEntity.FIRST_PAGE + target;
+            ItemStack from = binder.getItem(fromSlot);
+            ItemStack to = binder.getItem(toSlot);
+            binder.setItem(fromSlot, to);
+            binder.setItem(toSlot, from);
+            selectedPage = target;
+        } else if (id == IMPORT_NOTEBOOK) {
+            if (!binder.importNotebook()) return false;
+        } else return false;
+        refreshResult();
+        broadcastChanges();
+        return true;
+    }
+
+    private boolean clickStrip(int index) {
+        ItemStack carried = getCarried();
+        if (carried.is(ModItems.NOTEBOOK.get())) {
+            ItemStack emptied = binder.importNotebookFromStack(carried, Math.min(index == 0 ? 0 : index - 1,
+                    binder.nextPageIndex()));
+            if (emptied.isEmpty()) return false;
+            setCarried(emptied);
+            return true;
+        }
+        if (!carried.isEmpty()) {
+            if (index == 0) {
+                if (!binder.getItem(BookBinderBlockEntity.LINK_PANEL).isEmpty()
+                        || !binder.canPlaceItem(BookBinderBlockEntity.LINK_PANEL, carried)) return false;
+                binder.setItem(BookBinderBlockEntity.LINK_PANEL, carried.copyWithCount(1));
+            } else if (!binder.insertPage(index - 1, carried.copyWithCount(1))) return false;
+            ItemStack remainder = carried.copy();
+            remainder.shrink(1);
+            setCarried(remainder);
+            return true;
+        }
+        ItemStack removed;
+        if (index == 0) {
+            removed = binder.removeItem(BookBinderBlockEntity.LINK_PANEL, 1);
+        } else {
+            removed = binder.takePage(index - 1);
+        }
+        if (removed.isEmpty()) return false;
+        setCarried(removed);
+        return true;
+    }
+
+    @Override public ItemStack quickMoveStack(Player player, int index) {
+        if (!stillValid(player) || index < 0 || index >= slots.size()) return ItemStack.EMPTY;
+        if (index == RESULT) {
+            refreshResult();
+            if (!binder.canAssemble()) return ItemStack.EMPTY;
+            ItemStack book = binder.previewBook();
+            ItemStack remainder = book.copy();
+            if (!moveItemStackTo(remainder, PLAYER_START, slots.size(), true) || !remainder.isEmpty()) {
+                return ItemStack.EMPTY;
+            }
+            binder.consumeAssembly();
+            refreshResult();
+            return book;
+        }
+        Slot sourceSlot = slots.get(index);
+        if (!sourceSlot.hasItem()) return ItemStack.EMPTY;
+        ItemStack source = sourceSlot.getItem();
+        ItemStack original = source.copy();
+        boolean moved;
+        if (index < RESULT) {
+            moved = moveItemStackTo(source, PLAYER_START, slots.size(), true);
+        } else if (source.is(Items.LEATHER) || BookBinderBlockEntity.validCover(source)) {
+            moved = moveItemStackTo(source, BookBinderBlockEntity.COVER, BookBinderBlockEntity.COVER + 1, false);
+        } else if (source.is(ModItems.NOTEBOOK.get())) {
+            ItemStack emptied = binder.importNotebookFromStack(source, binder.nextPageIndex());
+            if (emptied.isEmpty()) return ItemStack.EMPTY;
+            sourceSlot.setByPlayer(emptied);
+            refreshResult();
+            return original;
+        } else if (source.is(ModItems.PAGE.get())
+                && PageItem.content(source).kind() == PageContent.Kind.LINK_PANEL) {
+            moved = moveItemStackTo(source, BookBinderBlockEntity.LINK_PANEL,
+                    BookBinderBlockEntity.LINK_PANEL + 1, false);
+        } else if (source.is(ModItems.PAGE.get())) {
+            moved = moveItemStackTo(source, BookBinderBlockEntity.FIRST_PAGE, RESULT, false);
+        } else moved = false;
+        if (!moved) return ItemStack.EMPTY;
+        if (source.isEmpty()) sourceSlot.setByPlayer(ItemStack.EMPTY);
+        else sourceSlot.setChanged();
+        refreshResult();
+        return original;
+    }
+
+    @Override public void clicked(int slotId, int button, ClickType clickType, Player player) {
+        if (!stillValid(player)) {
+            player.closeContainer();
+            return;
+        }
+        refreshResult();
+        super.clicked(slotId, button, clickType, player);
+    }
+
+    @Override public void broadcastChanges() {
+        refreshResult();
+        super.broadcastChanges();
+    }
+
+    private void refreshResult() {
+        if (clientSide) return;
+        ItemStack preview = binder == null ? ItemStack.EMPTY : binder.previewBook();
+        if (!ItemStack.matches(result.getItem(0), preview)) result.setItem(0, preview);
+    }
+
+    private final class BinderSlot extends Slot {
+        private final int capacity;
+        private BinderSlot(int index, int x, int y, int capacity) {
+            super(inputs, index, x, y);
+            this.capacity = capacity;
+        }
+        @Override public boolean mayPlace(ItemStack stack) { return inputs.canPlaceItem(getContainerSlot(), stack); }
+        @Override public int getMaxStackSize() { return capacity; }
+    }
+
+    private final class ResultSlot extends Slot {
+        private ResultSlot(Container container, int index, int x, int y) { super(container, index, x, y); }
+        @Override public boolean mayPlace(ItemStack stack) { return false; }
+        @Override public boolean mayPickup(Player player) {
+            return clientSide ? hasItem() : stillValid(player) && binder.canAssemble();
+        }
+        @Override public void onTake(Player player, ItemStack stack) {
+            if (!clientSide && binder.consumeAssembly()) refreshResult();
+            super.onTake(player, stack);
+        }
+    }
+}

src/main/java/net/dnorberg/rivencraft/menu/WritingDeskMenu.java

@@ -29,14 +29,27 @@ import net.minecraft.world.item.Items;
 
 public final class WritingDeskMenu extends AbstractContainerMenu {
     public static final int COPY_RESULT = WritingDeskBlockEntity.SIZE;
+    public static final int VISIBLE_TABS = 4;
+    public static final int PREVIOUS_TABS = 90;
+    public static final int NEXT_TABS = 91;
+    public static final int PAGE_BUTTON_BASE = 128;
+    public static final int CATALOG_BUTTON_BASE = 512;
+    public static final int ALL_PAGE_BUTTON_BASE = 32768;
+    public static final int PLACE_PAGE_BUTTON_BASE = 65536;
+    private static final int PAGE_ADDRESS_COUNT = WritingDeskBlockEntity.COLLECTIONS * NotebookContents.MAX_PAGES;
+    public static final int MOVE_PAGE_BUTTON_BASE = PLACE_PAGE_BUTTON_BASE + PAGE_ADDRESS_COUNT;
     private static final int PLAYER_START = COPY_RESULT + 1;
+    private static final int EXTRACT_TARGET_COUNT = PLAYER_START + 36 + 1;
+    public static final int EXTRACT_PAGE_BUTTON_BASE = MOVE_PAGE_BUTTON_BASE + PAGE_ADDRESS_COUNT * PAGE_ADDRESS_COUNT;
     private final Container desk;
     private final WritingDeskBlockEntity blockEntity;
     private final SimpleContainer result = new SimpleContainer(1);
     private final boolean clientSide;
     private int syncedActiveCollection;
     private int syncedInkRemaining;
+    private int firstVisibleTab;
     private int selectedPage;
+    private int selectedCollection = -1;
     private ResourceLocation selectedSymbol;
     private List<SymbolDisplayMetadata> catalog = List.of();
     private final ServerPlayer serverViewer;
@@ -54,6 +67,11 @@ public final class WritingDeskMenu extends AbstractContainerMenu {
         this.clientSide = inventory.player.level().isClientSide;
         this.serverViewer = inventory.player instanceof ServerPlayer serverPlayer ? serverPlayer : null;
         if (blockEntity != null && !clientSide) catalog = WritingDeskCatalog.available(blockEntity);
+        firstVisibleTab = blockEntity == null ? 0 : blockEntity.activeCollection() / VISIBLE_TABS * VISIBLE_TABS;
+        addDataSlot(new DataSlot() {
+            @Override public int get() { return firstVisibleTab; }
+            @Override public void set(int value) { firstVisibleTab = value; }
+        });
         addDataSlot(new DataSlot() {
             @Override public int get() { return WritingDeskMenu.this.blockEntity == null
                     ? syncedActiveCollection : WritingDeskMenu.this.blockEntity.activeCollection(); }
@@ -65,43 +83,94 @@ public final class WritingDeskMenu extends AbstractContainerMenu {
             @Override public void set(int value) { syncedInkRemaining = value; }
         });
         for (int i = 0; i < WritingDeskBlockEntity.COLLECTIONS; i++) {
-            addSlot(new DeskSlot(desk, i, 12, 20 + i * 37, 1));
+            addSlot(new DeskSlot(desk, i, 37, 34 + (i % VISIBLE_TABS) * 37, 1));
         }
-        addSlot(new DeskSlot(desk, WritingDeskBlockEntity.INK, 370, 20, 16));
+        addSlot(new DeskSlot(desk, WritingDeskBlockEntity.INK, 385, 28, 16));
-        addSlot(new DeskSlot(desk, WritingDeskBlockEntity.RETURN, 370, 57, 64));
+        addSlot(new DeskSlot(desk, WritingDeskBlockEntity.RETURN, 385, 80, 64));
-        addSlot(new DeskSlot(desk, WritingDeskBlockEntity.PAPER, 228, 20, 64));
+        addSlot(new DeskSlot(desk, WritingDeskBlockEntity.PAPER, 241, 28, 64));
         addSlot(new DeskSlot(desk, WritingDeskBlockEntity.LEGACY_OUTPUT, -1000, -1000, 64));
-        addSlot(new CopySlot(result, 0, 228, 57));
+        addSlot(new CopySlot(result, 0, 241, 80));
         for (int row = 0; row < 3; row++) {
             for (int column = 0; column < 9; column++) {
-                addSlot(new Slot(inventory, column + row * 9 + 9, 224 + column * 18, 91 + row * 18));
+                addSlot(new Slot(inventory, column + row * 9 + 9, 241 + column * 18, 104 + row * 18));
             }
         }
         for (int column = 0; column < 9; column++) {
-            addSlot(new Slot(inventory, column, 224 + column * 18, 149));
+            addSlot(new Slot(inventory, column, 241 + column * 18, 162));
         }
     }
 
     public int activeCollection() { return syncedActiveCollection; }
+    public int firstVisibleTab() { return firstVisibleTab; }
     public int inkRemaining() { return syncedInkRemaining; }
+    public int pageCapacity(int collectionIndex) {
+        if (collectionIndex < 0 || collectionIndex >= WritingDeskBlockEntity.COLLECTIONS) return 0;
+        ItemStack collection = desk.getItem(collectionIndex);
+        return collection.is(ModItems.NOTEBOOK.get()) ? NotebookContents.MAX_PAGES
+                : collection.is(ModItems.PAGE.get()) ? 1 : 0;
+    }
     public List<SymbolDisplayMetadata> catalog() { return catalog; }
     public void setCatalog(List<SymbolDisplayMetadata> symbols) { catalog = List.copyOf(symbols); }
 
+    public static int movePageButtonId(int sourceCollection, int sourcePage, int targetCollection, int targetPage) {
+        int source = sourceCollection * NotebookContents.MAX_PAGES + sourcePage;
+        int target = targetCollection * NotebookContents.MAX_PAGES + targetPage;
+        return MOVE_PAGE_BUTTON_BASE + source * PAGE_ADDRESS_COUNT + target;
+    }
+
+    /** targetSlot is -1 for the cursor, otherwise a visible player or desk-tab slot. */
+    public static int extractPageButtonId(int sourceCollection, int sourcePage, int targetSlot) {
+        int source = sourceCollection * NotebookContents.MAX_PAGES + sourcePage;
+        return EXTRACT_PAGE_BUTTON_BASE + source * EXTRACT_TARGET_COUNT + targetSlot + 1;
+    }
+
     @Override public boolean clickMenuButton(Player player, int id) {
         if (blockEntity == null || !stillValid(player)) return false;
-        if (id >= 0 && id < WritingDeskBlockEntity.COLLECTIONS) {
+        if (id == PREVIOUS_TABS || id == NEXT_TABS) {
+            firstVisibleTab = Math.clamp(firstVisibleTab + (id == NEXT_TABS ? VISIBLE_TABS : -VISIBLE_TABS),
+                    0, WritingDeskBlockEntity.COLLECTIONS - VISIBLE_TABS);
+            return true;
+        } else if (id >= 0 && id < WritingDeskBlockEntity.COLLECTIONS) {
+            if (id < firstVisibleTab || id >= firstVisibleTab + VISIBLE_TABS) return false;
             blockEntity.setActiveCollection(id);
             selectedPage = 0;
+            selectedCollection = -1;
             selectedSymbol = null;
-        } else if (id >= 16 && id < 16 + NotebookContents.MAX_PAGES) {
+        } else if (id >= EXTRACT_PAGE_BUTTON_BASE
-            selectedPage = id - 16;
+                && id < EXTRACT_PAGE_BUTTON_BASE + PAGE_ADDRESS_COUNT * EXTRACT_TARGET_COUNT) {
+            int offset = id - EXTRACT_PAGE_BUTTON_BASE;
+            int source = offset / EXTRACT_TARGET_COUNT;
+            int targetSlot = offset % EXTRACT_TARGET_COUNT - 1;
+            if (!extractPage(source / NotebookContents.MAX_PAGES, source % NotebookContents.MAX_PAGES,
+                    targetSlot)) return false;
+        } else if (id >= MOVE_PAGE_BUTTON_BASE && id < MOVE_PAGE_BUTTON_BASE + PAGE_ADDRESS_COUNT * PAGE_ADDRESS_COUNT) {
+            int offset = id - MOVE_PAGE_BUTTON_BASE;
+            int source = offset / PAGE_ADDRESS_COUNT;
+            int target = offset % PAGE_ADDRESS_COUNT;
+            if (!movePage(source / NotebookContents.MAX_PAGES, source % NotebookContents.MAX_PAGES,
+                    target / NotebookContents.MAX_PAGES, target % NotebookContents.MAX_PAGES)) return false;
+        } else if (id >= PLACE_PAGE_BUTTON_BASE
+                && id < PLACE_PAGE_BUTTON_BASE + WritingDeskBlockEntity.COLLECTIONS * NotebookContents.MAX_PAGES) {
+            int offset = id - PLACE_PAGE_BUTTON_BASE;
+            if (!placeCarriedPage(offset / NotebookContents.MAX_PAGES, offset % NotebookContents.MAX_PAGES)) return false;
+        } else if (id >= PAGE_BUTTON_BASE && id < PAGE_BUTTON_BASE + NotebookContents.MAX_PAGES) {
+            selectedPage = id - PAGE_BUTTON_BASE;
+            selectedCollection = -1;
             selectedSymbol = null;
-        } else if (id >= 100 && id < 100 + catalog.size()) {
+        } else if (id >= ALL_PAGE_BUTTON_BASE && id < ALL_PAGE_BUTTON_BASE + WritingDeskBlockEntity.COLLECTIONS * NotebookContents.MAX_PAGES) {
+            int offset = id - ALL_PAGE_BUTTON_BASE;
+            int collection = offset / NotebookContents.MAX_PAGES;
+            int page = offset % NotebookContents.MAX_PAGES;
+            if (pageAt(collection, page).isEmpty()) return false;
+            selectedCollection = collection;
+            selectedPage = page;
+            selectedSymbol = null;
+        } else if (id >= CATALOG_BUTTON_BASE && id < CATALOG_BUTTON_BASE + catalog.size()) {
             if (!catalog.equals(WritingDeskCatalog.available(blockEntity))) {
                 refreshCatalog();
                 return false;
             }
-            ResourceLocation requested = catalog.get(id - 100).id();
+            ResourceLocation requested = catalog.get(id - CATALOG_BUTTON_BASE).id();
             if (!WritingDeskCatalog.available(blockEntity).stream().anyMatch(entry -> entry.id().equals(requested))) {
                 return false;
             }
@@ -111,6 +180,129 @@ public final class WritingDeskMenu extends AbstractContainerMenu {
         return true;
     }
 
+    private boolean placeCarriedPage(int collectionIndex, int pageIndex) {
+        // Resolve the actual storage position on the server, never a filtered list index.
+        ItemStack carried = getCarried();
+        if (clientSide || !carried.is(ModItems.PAGE.get())) return false;
+        ItemStack collection = desk.getItem(collectionIndex);
+        if (collection.is(ModItems.NOTEBOOK.get())) {
+            var pages = new java.util.ArrayList<>(collection.getOrDefault(
+                    ModDataComponents.NOTEBOOK_CONTENTS.get(), NotebookContents.EMPTY).pages());
+            while (pages.size() <= pageIndex) pages.add(ItemStack.EMPTY);
+            if (!pages.get(pageIndex).isEmpty()) return false;
+            pages.set(pageIndex, carried.copyWithCount(1));
+            ItemStack updated = collection.copy();
+            updated.set(ModDataComponents.NOTEBOOK_CONTENTS.get(), new NotebookContents(pages));
+            desk.setItem(collectionIndex, updated);
+        } else return false;
+        carried.shrink(1);
+        setCarried(carried.isEmpty() ? ItemStack.EMPTY : carried);
+        selectedCollection = collectionIndex;
+        selectedPage = pageIndex;
+        selectedSymbol = null;
+        refreshCatalog();
+        broadcastChanges();
+        return true;
+    }
+
+    private boolean movePage(int sourceCollection, int sourcePage, int targetCollection, int targetPage) {
+        if (!getCarried().isEmpty() || sourceCollection == targetCollection && sourcePage == targetPage) return false;
+        ItemStack sourceBook = desk.getItem(sourceCollection);
+        ItemStack targetBook = desk.getItem(targetCollection);
+        boolean sourceNotebook = sourceBook.is(ModItems.NOTEBOOK.get());
+        boolean targetNotebook = targetBook.is(ModItems.NOTEBOOK.get());
+        if ((!sourceNotebook && (!sourceBook.is(ModItems.PAGE.get()) || sourcePage != 0))
+                || (!targetNotebook && (!targetBook.is(ModItems.PAGE.get()) || targetPage != 0))) return false;
+        var sourcePages = sourceNotebook ? new java.util.ArrayList<>(sourceBook.getOrDefault(
+                ModDataComponents.NOTEBOOK_CONTENTS.get(), NotebookContents.EMPTY).pages()) : null;
+        if (sourceNotebook && (sourcePage >= sourcePages.size() || sourcePages.get(sourcePage).isEmpty())) return false;
+        ItemStack moving = sourceNotebook ? sourcePages.get(sourcePage) : sourceBook;
+        if (moving.getCount() != 1) return false;
+        if (!targetNotebook && targetBook.getCount() != 1) return false;
+        var targetPages = targetNotebook ? sourceCollection == targetCollection ? sourcePages
+                : new java.util.ArrayList<>(targetBook.getOrDefault(
+                        ModDataComponents.NOTEBOOK_CONTENTS.get(), NotebookContents.EMPTY).pages()) : null;
+        if (targetNotebook) while (targetPages.size() <= targetPage) targetPages.add(ItemStack.EMPTY);
+        ItemStack displaced = targetNotebook ? targetPages.get(targetPage) : targetBook;
+        if (targetNotebook) targetPages.set(targetPage, moving);
+        if (sourceNotebook) {
+            sourcePages.set(sourcePage, displaced);
+            ItemStack updatedSource = sourceBook.copy();
+            updatedSource.set(ModDataComponents.NOTEBOOK_CONTENTS.get(), new NotebookContents(sourcePages));
+            desk.setItem(sourceCollection, updatedSource);
+        } else desk.setItem(sourceCollection, displaced.isEmpty() ? ItemStack.EMPTY : displaced.copyWithCount(1));
+        if (targetNotebook && sourceCollection != targetCollection) {
+            ItemStack updatedTarget = targetBook.copy();
+            updatedTarget.set(ModDataComponents.NOTEBOOK_CONTENTS.get(), new NotebookContents(targetPages));
+            desk.setItem(targetCollection, updatedTarget);
+        } else if (!targetNotebook) desk.setItem(targetCollection, moving.copyWithCount(1));
+        selectedCollection = targetCollection;
+        selectedPage = targetPage;
+        selectedSymbol = null;
+        refreshCatalog();
+        broadcastChanges();
+        return true;
+    }
+
+    private boolean extractPage(int sourceCollection, int sourcePage, int targetSlot) {
+        if (!getCarried().isEmpty() || targetSlot < -1 || targetSlot >= slots.size()) return false;
+        ItemStack sourceBook = desk.getItem(sourceCollection);
+        boolean sourceNotebook = sourceBook.is(ModItems.NOTEBOOK.get());
+        if (!sourceNotebook && (!sourceBook.is(ModItems.PAGE.get()) || sourcePage != 0)) return false;
+        var sourcePages = sourceNotebook ? new java.util.ArrayList<>(sourceBook.getOrDefault(
+                ModDataComponents.NOTEBOOK_CONTENTS.get(), NotebookContents.EMPTY).pages()) : null;
+        if (sourceNotebook && (sourcePage >= sourcePages.size() || sourcePages.get(sourcePage).isEmpty())) return false;
+        ItemStack moving = sourceNotebook ? sourcePages.get(sourcePage).copyWithCount(1) : sourceBook.copyWithCount(1);
+        if (!sourceNotebook && sourceBook.getCount() != 1) return false;
+
+        if (targetSlot == -1) {
+            setCarried(moving);
+        } else {
+            if (targetSlot >= WritingDeskBlockEntity.COLLECTIONS && targetSlot < PLAYER_START) return false;
+            Slot target = slots.get(targetSlot);
+            if (!target.isActive() || !target.mayPlace(moving)) return false;
+            ItemStack current = target.getItem();
+            if (targetSlot < WritingDeskBlockEntity.COLLECTIONS && current.is(ModItems.NOTEBOOK.get())) {
+                var targetPages = targetSlot == sourceCollection ? sourcePages
+                        : new java.util.ArrayList<>(current.getOrDefault(
+                                ModDataComponents.NOTEBOOK_CONTENTS.get(), NotebookContents.EMPTY).pages());
+                int position = -1;
+                for (int i = 0; i < NotebookContents.MAX_PAGES; i++) {
+                    if (i >= targetPages.size() || targetPages.get(i).isEmpty()) {
+                        position = i;
+                        break;
+                    }
+                }
+                if (position < 0) return false;
+                while (targetPages.size() <= position) targetPages.add(ItemStack.EMPTY);
+                targetPages.set(position, moving);
+                if (targetSlot != sourceCollection) {
+                    ItemStack updatedTarget = current.copy();
+                    updatedTarget.set(ModDataComponents.NOTEBOOK_CONTENTS.get(), new NotebookContents(targetPages));
+                    target.setByPlayer(updatedTarget);
+                }
+            } else if (current.isEmpty()) {
+                target.setByPlayer(moving);
+            } else if (targetSlot >= PLAYER_START && ItemStack.isSameItemSameComponents(current, moving)
+                    && current.getCount() < target.getMaxStackSize(moving)) {
+                target.setByPlayer(current.copyWithCount(current.getCount() + 1));
+            } else return false;
+        }
+
+        if (sourceNotebook) {
+            sourcePages.set(sourcePage, ItemStack.EMPTY);
+            ItemStack updatedSource = sourceBook.copy();
+            updatedSource.set(ModDataComponents.NOTEBOOK_CONTENTS.get(), new NotebookContents(sourcePages));
+            desk.setItem(sourceCollection, updatedSource);
+        } else desk.setItem(sourceCollection, ItemStack.EMPTY);
+        selectedCollection = sourceCollection;
+        selectedPage = sourcePage;
+        selectedSymbol = null;
+        refreshCatalog();
+        broadcastChanges();
+        return true;
+    }
+
     @Override public boolean stillValid(Player player) {
         return blockEntity != null && blockEntity.stillValid(player);
     }
@@ -130,6 +322,7 @@ public final class WritingDeskMenu extends AbstractContainerMenu {
             return copy;
         }
         Slot slot = slots.get(index);
+        if (!slot.isActive()) return ItemStack.EMPTY;
         if (!slot.hasItem()) return ItemStack.EMPTY;
         ItemStack moving = slot.getItem();
         ItemStack original = moving.copy();
@@ -144,12 +337,13 @@ public final class WritingDeskMenu extends AbstractContainerMenu {
     }
 
     private boolean moveIntoDesk(ItemStack moving) {
-        if (moving.is(ModItems.INK_VIAL.get())) return moveItemStackTo(moving, 4, 5, false);
+        if (moving.is(ModItems.INK_VIAL.get())) return moveItemStackTo(moving,
-        if (moving.is(ModItems.NOTEBOOK.get())) return moveItemStackTo(moving, 0, 4, false);
+                WritingDeskBlockEntity.INK, WritingDeskBlockEntity.INK + 1, false);
+        if (moving.is(ModItems.NOTEBOOK.get())) return moveItemStackTo(moving, firstVisibleTab, firstVisibleTab + VISIBLE_TABS, false);
         if (moving.is(Items.PAPER))
             return moveItemStackTo(moving, WritingDeskBlockEntity.PAPER,
                     WritingDeskBlockEntity.PAPER + 1, false);
-        if (moving.is(ModItems.PAGE.get())) return moveItemStackTo(moving, 0, 4, false);
+        if (moving.is(ModItems.PAGE.get())) return moveItemStackTo(moving, firstVisibleTab, firstVisibleTab + VISIBLE_TABS, false);
         return false;
     }
 
@@ -162,12 +356,20 @@ public final class WritingDeskMenu extends AbstractContainerMenu {
                     .anyMatch(entry -> entry.id().equals(selectedSymbol))
                     ? PageItem.createSymbolPage(reference) : ItemStack.EMPTY;
         }
-        ItemStack collection = desk.getItem(blockEntity == null ? syncedActiveCollection : blockEntity.activeCollection());
+        int collectionIndex = selectedCollection >= 0 ? selectedCollection
-        if (collection.is(ModItems.PAGE.get())) return selectedPage == 0 ? collection : ItemStack.EMPTY;
+                : blockEntity == null ? syncedActiveCollection : blockEntity.activeCollection();
+        return pageAt(collectionIndex, selectedPage);
+    }
+
+    private ItemStack pageAt(int collectionIndex, int pageIndex) {
+        if (collectionIndex < 0 || collectionIndex >= WritingDeskBlockEntity.COLLECTIONS
+                || pageIndex < 0 || pageIndex >= NotebookContents.MAX_PAGES) return ItemStack.EMPTY;
+        ItemStack collection = desk.getItem(collectionIndex);
+        if (collection.is(ModItems.PAGE.get())) return pageIndex == 0 ? collection : ItemStack.EMPTY;
         if (collection.is(ModItems.NOTEBOOK.get())) {
             List<ItemStack> pages = collection.getOrDefault(
                     ModDataComponents.NOTEBOOK_CONTENTS.get(), NotebookContents.EMPTY).pages();
-            return selectedPage < pages.size() ? pages.get(selectedPage) : ItemStack.EMPTY;
+            return pageIndex < pages.size() ? pages.get(pageIndex) : ItemStack.EMPTY;
         }
         return ItemStack.EMPTY;
     }
@@ -211,6 +413,7 @@ public final class WritingDeskMenu extends AbstractContainerMenu {
         }
         refreshCatalog();
         refreshOutput();
+        if (slotId >= 0 && slotId < slots.size() && !slots.get(slotId).isActive()) return;
         super.clicked(slotId, button, clickType, player);
     }
 
@@ -226,13 +429,19 @@ public final class WritingDeskMenu extends AbstractContainerMenu {
         }
     }
 
-    private static final class DeskSlot extends Slot {
+    private final class DeskSlot extends Slot {
         private final int limit;
         private DeskSlot(Container container, int index, int x, int y, int limit) {
             super(container, index, x, y);
             this.limit = limit;
         }
-        @Override public boolean mayPlace(ItemStack stack) { return container.canPlaceItem(getContainerSlot(), stack); }
+        @Override public boolean isActive() {
+            int slot = getContainerSlot();
+            return slot >= WritingDeskBlockEntity.COLLECTIONS
+                    || slot >= firstVisibleTab && slot < firstVisibleTab + VISIBLE_TABS;
+        }
+        @Override public boolean mayPickup(Player player) { return isActive(); }
+        @Override public boolean mayPlace(ItemStack stack) { return isActive() && container.canPlaceItem(getContainerSlot(), stack); }
         @Override public int getMaxStackSize() { return limit; }
     }
 }

src/main/java/net/dnorberg/rivencraft/network/ModNetworking.java

@@ -13,6 +13,7 @@ import net.dnorberg.rivencraft.client.ClientWritingDeskCatalog;
 import net.dnorberg.rivencraft.event.AgeCelestialAngleSync;
 import net.dnorberg.rivencraft.item.DescriptiveBookItem;
 import net.dnorberg.rivencraft.item.LinkingBookItem;
+import net.dnorberg.rivencraft.menu.BookBinderMenu;
 import net.dnorberg.rivencraft.registry.ModDataComponents;
 import net.dnorberg.rivencraft.registry.ModItems;
 import net.minecraft.core.component.DataComponents;
@@ -49,7 +50,7 @@ public final class ModNetworking {
     }
 
     public static void register(RegisterPayloadHandlersEvent event) {
-        PayloadRegistrar registrar = event.registrar("10");
+        PayloadRegistrar registrar = event.registrar("12");
         registrar.playToServer(RequestDescriptiveBookScreenPayload.TYPE, RequestDescriptiveBookScreenPayload.STREAM_CODEC,
                 ModNetworking::requestDescriptiveBookScreen);
         registrar.playToClient(OpenDescriptiveBookScreenPayload.TYPE, OpenDescriptiveBookScreenPayload.STREAM_CODEC,
@@ -71,6 +72,16 @@ public final class ModNetworking {
                 ClientAgeCelestialAngles::handle);
         registrar.playToClient(WritingDeskCatalogPayload.TYPE, WritingDeskCatalogPayload.STREAM_CODEC,
                 ClientWritingDeskCatalog::handle);
+        registrar.playToServer(SetBookBinderTitlePayload.TYPE, SetBookBinderTitlePayload.STREAM_CODEC,
+                ModNetworking::setBookBinderTitle);
+    }
+
+    private static void setBookBinderTitle(SetBookBinderTitlePayload payload, IPayloadContext context) {
+        if (context.player() instanceof ServerPlayer player
+                && player.containerMenu instanceof BookBinderMenu menu
+                && menu.containerId == payload.containerId()) {
+            menu.setTitle(player, payload.title());
+        }
     }
 
     private static void requestDescriptiveBookScreen(RequestDescriptiveBookScreenPayload payload, IPayloadContext context) {

src/main/java/net/dnorberg/rivencraft/network/SetBookBinderTitlePayload.java

@@ -0,0 +1,19 @@
+package net.dnorberg.rivencraft.network;
+
+import net.dnorberg.rivencraft.Rivencraft;
+import net.minecraft.network.RegistryFriendlyByteBuf;
+import net.minecraft.network.codec.ByteBufCodecs;
+import net.minecraft.network.codec.StreamCodec;
+import net.minecraft.network.protocol.common.custom.CustomPacketPayload;
+import net.minecraft.resources.ResourceLocation;
+
+public record SetBookBinderTitlePayload(int containerId, String title) implements CustomPacketPayload {
+    public static final Type<SetBookBinderTitlePayload> TYPE = new Type<>(
+            ResourceLocation.fromNamespaceAndPath(Rivencraft.MOD_ID, "set_book_binder_title"));
+    public static final StreamCodec<RegistryFriendlyByteBuf, SetBookBinderTitlePayload> STREAM_CODEC =
+            StreamCodec.composite(ByteBufCodecs.VAR_INT, SetBookBinderTitlePayload::containerId,
+                    ByteBufCodecs.STRING_UTF8, SetBookBinderTitlePayload::title,
+                    SetBookBinderTitlePayload::new);
+
+    @Override public Type<? extends CustomPacketPayload> type() { return TYPE; }
+}

src/main/java/net/dnorberg/rivencraft/registry/ModBlockEntities.java

@@ -2,6 +2,7 @@ package net.dnorberg.rivencraft.registry;
 
 import net.dnorberg.rivencraft.Rivencraft;
 import net.dnorberg.rivencraft.block.entity.BookStandBlockEntity;
+import net.dnorberg.rivencraft.block.entity.BookBinderBlockEntity;
 import net.dnorberg.rivencraft.block.entity.WritingDeskBlockEntity;
 import net.minecraft.core.registries.Registries;
 import net.minecraft.world.level.block.entity.BlockEntityType;
@@ -20,6 +21,9 @@ public final class ModBlockEntities {
     public static final DeferredHolder<BlockEntityType<?>, BlockEntityType<WritingDeskBlockEntity>> WRITING_DESK =
             BLOCK_ENTITIES.register("writing_desk", () -> BlockEntityType.Builder
                     .of(WritingDeskBlockEntity::new, ModBlocks.WRITING_DESK.get()).build(null));
+    public static final DeferredHolder<BlockEntityType<?>, BlockEntityType<BookBinderBlockEntity>> BOOK_BINDER =
+            BLOCK_ENTITIES.register("book_binder", () -> BlockEntityType.Builder
+                    .of(BookBinderBlockEntity::new, ModBlocks.BOOK_BINDER.get()).build(null));
 
     private ModBlockEntities() {
     }

src/main/java/net/dnorberg/rivencraft/registry/ModBlocks.java

@@ -2,6 +2,7 @@ package net.dnorberg.rivencraft.registry;
 
 import net.dnorberg.rivencraft.Rivencraft;
 import net.dnorberg.rivencraft.block.BookStandBlock;
+import net.dnorberg.rivencraft.block.BookBinderBlock;
 import net.dnorberg.rivencraft.block.WritingDeskBlock;
 import net.minecraft.world.level.block.Blocks;
 import net.minecraft.world.level.block.state.BlockBehaviour;
@@ -21,6 +22,10 @@ public final class ModBlocks {
             "writing_desk", WritingDeskBlock::new,
             BlockBehaviour.Properties.ofFullCopy(Blocks.CRAFTING_TABLE).noOcclusion()
     );
+    public static final DeferredBlock<BookBinderBlock> BOOK_BINDER = BLOCKS.registerBlock(
+            "book_binder", BookBinderBlock::new,
+            BlockBehaviour.Properties.ofFullCopy(Blocks.CRAFTING_TABLE).noOcclusion()
+    );
 
     private ModBlocks() {
     }

src/main/java/net/dnorberg/rivencraft/registry/ModCreativeTabs.java

@@ -23,6 +23,7 @@ public final class ModCreativeTabs {
                         output.accept(ModItems.NOTEBOOK.get());
                         output.accept(ModItems.INK_VIAL.get());
                         output.accept(ModItems.WRITING_DESK.get());
+                        output.accept(ModItems.BOOK_BINDER.get());
                     })
                     .build());
 

src/main/java/net/dnorberg/rivencraft/registry/ModDataComponents.java

@@ -5,6 +5,7 @@ import net.dnorberg.rivencraft.book.LinkTarget;
 import net.dnorberg.rivencraft.book.AgeReference;
 import net.dnorberg.rivencraft.writing.PageContent;
 import net.dnorberg.rivencraft.writing.NotebookContents;
+import net.dnorberg.rivencraft.writing.OrderedWriting;
 import net.dnorberg.rivencraft.writing.SymbolDisplayMetadata;
 import com.mojang.serialization.Codec;
 import net.minecraft.core.component.DataComponentType;
@@ -61,6 +62,12 @@ public final class ModDataComponents {
                     .networkSynchronized(NotebookContents.STREAM_CODEC)
                     .cacheEncoding()
                     .build());
+    public static final DeferredHolder<DataComponentType<?>, DataComponentType<OrderedWriting>> BOOK_WRITING =
+            DATA_COMPONENTS.register("book_writing", () -> DataComponentType.<OrderedWriting>builder()
+                    .persistent(OrderedWriting.CODEC)
+                    .networkSynchronized(OrderedWriting.STREAM_CODEC)
+                    .cacheEncoding()
+                    .build());
     public static final DeferredHolder<DataComponentType<?>, DataComponentType<Integer>> INK_REMAINING =
             DATA_COMPONENTS.register("ink_remaining", () -> DataComponentType.<Integer>builder()
                     .persistent(Codec.intRange(0, 16))

src/main/java/net/dnorberg/rivencraft/registry/ModItems.java

@@ -41,6 +41,7 @@ public final class ModItems {
             new Item.Properties().stacksTo(16)
     );
     public static final DeferredItem<BlockItem> WRITING_DESK = ITEMS.registerSimpleBlockItem(ModBlocks.WRITING_DESK);
+    public static final DeferredItem<BlockItem> BOOK_BINDER = ITEMS.registerSimpleBlockItem(ModBlocks.BOOK_BINDER);
 
     private ModItems() {
     }

src/main/java/net/dnorberg/rivencraft/registry/ModMenus.java

@@ -3,6 +3,7 @@ package net.dnorberg.rivencraft.registry;
 import net.dnorberg.rivencraft.Rivencraft;
 import net.dnorberg.rivencraft.menu.NotebookMenu;
 import net.dnorberg.rivencraft.menu.WritingDeskMenu;
+import net.dnorberg.rivencraft.menu.BookBinderMenu;
 import net.minecraft.core.registries.Registries;
 import net.minecraft.world.inventory.MenuType;
 import net.neoforged.bus.api.IEventBus;
@@ -18,6 +19,8 @@ public final class ModMenus {
             MENUS.register("notebook", () -> IMenuTypeExtension.create(NotebookMenu::new));
     public static final DeferredHolder<MenuType<?>, MenuType<WritingDeskMenu>> WRITING_DESK =
             MENUS.register("writing_desk", () -> IMenuTypeExtension.create(WritingDeskMenu::new));
+    public static final DeferredHolder<MenuType<?>, MenuType<BookBinderMenu>> BOOK_BINDER =
+            MENUS.register("book_binder", () -> IMenuTypeExtension.create(BookBinderMenu::new));
 
     private ModMenus() {
     }

src/main/resources/assets/rivencraft/blockstates/book_binder.json

@@ -0,0 +1,8 @@
+{
+  "variants": {
+    "facing=north": {"model":"rivencraft:block/book_binder"},
+    "facing=east": {"model":"rivencraft:block/book_binder","y":90},
+    "facing=south": {"model":"rivencraft:block/book_binder","y":180},
+    "facing=west": {"model":"rivencraft:block/book_binder","y":270}
+  }
+}

src/main/resources/assets/rivencraft/lang/en_us.json

@@ -18,6 +18,17 @@
   "item.rivencraft.ink_vial": "Ink Vial",
   "block.rivencraft.writing_desk": "Writing Desk",
   "container.rivencraft.writing_desk": "Writing Desk",
+  "block.rivencraft.book_binder": "Book Binder",
+  "container.rivencraft.book_binder": "Book Binder",
+  "screen.rivencraft.book_binder.title": "Book title",
+  "screen.rivencraft.book_binder.title_hint": "Name the book",
+  "screen.rivencraft.book_binder.missing_panel": "Link Panel required as the first page",
+  "screen.rivencraft.book_binder.cover": "Cover · Link Panel · Notebook",
+  "screen.rivencraft.book_binder.import": "Import Notebook",
+  "screen.rivencraft.book_binder.import.tooltip": "Move all Notebook pages into the binder in order",
+  "screen.rivencraft.book_binder.move_previous": "Move selected page left",
+  "screen.rivencraft.book_binder.move_next": "Move selected page right",
+  "screen.rivencraft.book_binder.select_hint": "Right-click page to select",
   "screen.rivencraft.writing_desk.ink": "Ink: %s/%s",
   "screen.rivencraft.writing_desk.search": "Search",
   "screen.rivencraft.writing_desk.no_symbols": "No available symbols",

src/main/resources/assets/rivencraft/models/block/book_binder.json

@@ -0,0 +1,61 @@
+{
+  "parent": "minecraft:block/block",
+  "textures": {
+    "particle": "rivencraft:block/book_binder",
+    "body": "rivencraft:block/book_binder",
+    "press": "rivencraft:block/book_binder_press"
+  },
+  "elements": [
+    {
+      "from": [0, 0, 0], "to": [16, 10, 16],
+      "faces": {
+        "north": {"texture":"#body","uv":[0,4,4,6.5]},
+        "east": {"texture":"#body","uv":[4,4,8,6.5]},
+        "south": {"texture":"#body","uv":[8,4,12,6.5]},
+        "west": {"texture":"#body","uv":[12,4,16,6.5]},
+        "up": {"texture":"#body","uv":[4,0,8,4]},
+        "down": {"texture":"#body","uv":[8,0,12,4]}
+      }
+    },
+    {
+      "from": [0, 10, 1], "to": [3, 14, 15],
+      "faces": {
+        "north": {"texture":"#press","uv":[0,4,1.5,6]},
+        "east": {"texture":"#press","uv":[0,0,7,2]},
+        "south": {"texture":"#press","uv":[2,4,3.5,6]},
+        "west": {"texture":"#press","uv":[0,2,7,4]},
+        "up": {"texture":"#press","uv":[7,0,8.5,6]},
+        "down": {"texture":"#press","uv":[8.5,0,10,7]}
+      }
+    },
+    {
+      "from": [13, 10, 1], "to": [16, 14, 15],
+      "faces": {
+        "north": {"texture":"#press","uv":[0,4,1.5,6]},
+        "east": {"texture":"#press","uv":[0,0,7,2]},
+        "south": {"texture":"#press","uv":[2,4,3.5,6]},
+        "west": {"texture":"#press","uv":[0,2,7,4]},
+        "up": {"texture":"#press","uv":[7,0,8.5,6]},
+        "down": {"texture":"#press","uv":[8.5,0,10,7]}
+      }
+    },
+    {
+      "from": [3, 11, 3], "to": [13, 12, 4],
+      "faces": {
+        "north": {"texture":"#press","uv":[1,15.5,6,16]},
+        "south": {"texture":"#press","uv":[7,15.5,12,16]},
+        "up": {"texture":"#press","uv":[0.5,15,5.5,15.5]},
+        "down": {"texture":"#press","uv":[5.5,15,10.5,15.5]}
+      }
+    },
+    {
+      "from": [3, 11, 12], "to": [13, 12, 13],
+      "faces": {
+        "north": {"texture":"#press","uv":[1,15.5,6,16]},
+        "south": {"texture":"#press","uv":[7,15.5,12,16]},
+        "up": {"texture":"#press","uv":[0.5,15,5.5,15.5]},
+        "down": {"texture":"#press","uv":[5.5,15,10.5,15.5]}
+      }
+    }
+  ]
+}

src/main/resources/assets/rivencraft/models/block/writing_desk.json

@@ -1,11 +1,62 @@
 {
-  "parent": "minecraft:block/block",
+	"format_version": "26.3",
-  "textures": {"wood":"rivencraft:block/writing_desk_wood","inlay":"rivencraft:block/writing_desk_inlay","particle":"rivencraft:block/writing_desk_wood"},
+	"credit": "Made with Blockbench",
-  "elements": [
+	"parent": "minecraft:block/block",
-    {"from":[0,0,1],"to":[16,1,15],"faces":{"up":{"texture":"#wood"},"down":{"texture":"#wood"},"north":{"texture":"#wood"},"south":{"texture":"#wood"},"east":{"texture":"#wood"},"west":{"texture":"#wood"}}},
+	"textures": {
-    {"from":[0,8,0],"to":[16,9,16],"faces":{"up":{"texture":"#inlay"},"down":{"texture":"#wood"},"north":{"texture":"#wood"},"south":{"texture":"#wood"},"east":{"texture":"#wood"},"west":{"texture":"#wood"}}},
+		"2": "rivencraft:block/writing_desk",
-    {"from":[0,0,1],"to":[1,8,15],"faces":{"up":{"texture":"#wood"},"down":{"texture":"#wood"},"north":{"texture":"#wood"},"south":{"texture":"#wood"},"east":{"texture":"#wood"},"west":{"texture":"#wood"}}},
+		"particle": "rivencraft:block/writing_desk"
-    {"from":[1,3,1],"to":[16,4,15],"faces":{"up":{"texture":"#wood"},"down":{"texture":"#wood"},"north":{"texture":"#wood"},"south":{"texture":"#wood"},"east":{"texture":"#wood"},"west":{"texture":"#wood"}}},
+	},
-    {"from":[0,9,15],"to":[16,15,16],"faces":{"up":{"texture":"#wood"},"down":{"texture":"#wood"},"north":{"texture":"#wood"},"south":{"texture":"#wood"},"east":{"texture":"#wood"},"west":{"texture":"#wood"}}}
+	"elements": [
-  ]
+		{
+			"from": [0, 11, 0],
+			"to": [16, 12, 16],
+			"rotation": {"angle": 0, "axis": "y", "origin": [0, 3, 0]},
+			"faces": {
+				"north": {"uv": [1, 2, 2, 2.125], "texture": "#2"},
+				"east": {"uv": [2.82031, 4.01563, 3.82031, 4.125], "texture": "#2"},
+				"south": {"uv": [0, 2, 1, 2.125], "texture": "#2"},
+				"west": {"uv": [2.9375, 0.125, 3, 2.125], "rotation": 90, "texture": "#2"},
+				"up": {"uv": [1, 0, 2, 2], "texture": "#2"},
+				"down": {"uv": [3, 0, 3.9375, 2], "texture": "#2"}
+			}
+		},
+		{
+			"from": [0, 0, 1],
+			"to": [1, 11, 15],
+			"faces": {
+				"north": {"uv": [7.6875, 2.625, 7.75, 4], "texture": "#2"},
+				"east": {"uv": [7.6875, 2.625, 6.6875, 4], "texture": "#2"},
+				"south": {"uv": [1.42188, 10.78125, 2.4375, 11.85938], "texture": "#2"},
+				"west": {"uv": [5.67969, 2.625, 6.6875, 4], "texture": "#2"},
+				"up": {"uv": [0.08594, 10.36719, 1.14063, 11.83594], "texture": "#2"},
+				"down": {"uv": [5.75, 5.25, 5.8125, 7.10938], "texture": "#2"}
+			}
+		},
+		{
+			"from": [1, 5, 1],
+			"to": [16, 6, 15],
+			"rotation": {"angle": 0, "axis": "y", "origin": [0, 2, 0]},
+			"faces": {
+				"north": {"uv": [3, 2, 3.9375, 2.125], "texture": "#2"},
+				"east": {"uv": [2.8125, 4, 3.75, 4.125], "texture": "#2"},
+				"south": {"uv": [1.35938, 11.71875, 2.44531, 12.71875], "texture": "#2"},
+				"west": {"uv": [0.03125, 11.66406, 0.99219, 12.66406], "texture": "#2"},
+				"up": {"uv": [1.875, 4, 2.8125, 2.125], "texture": "#2"},
+				"down": {"uv": [0.9375, 2.125, 1.875, 4], "texture": "#2"}
+			}
+		},
+		{
+			"from": [0, 0, 15],
+			"to": [16, 11, 16],
+			"rotation": {"angle": 0, "axis": "y", "origin": [0, -9, 0]},
+			"faces": {
+				"north": {"uv": [8.0625, 0, 9.0625, 1.375], "texture": "#2"},
+				"east": {"uv": [6.625, 0.125, 6.6875, 1.5], "texture": "#2"},
+				"south": {"uv": [5.625, 2.625, 6.625, 4], "texture": "#2"},
+				"west": {"uv": [7.6875, 2.625, 7.75, 4], "texture": "#2"},
+				"up": {"uv": [0, 15, 16, 16], "texture": "#2"},
+				"down": {"uv": [0, 9.17969, 16, 10.17969], "texture": "#2"}
+			}
+		}
+	]
 }

src/main/resources/assets/rivencraft/models/block/writing_desk_extension.json

@@ -1,11 +1,88 @@
 {
-  "parent": "minecraft:block/block",
+	"format_version": "26.3",
-  "textures": {"wood":"rivencraft:block/writing_desk_wood","inlay":"rivencraft:block/writing_desk_inlay","particle":"rivencraft:block/writing_desk_wood"},
+	"credit": "Made with Blockbench",
-  "elements": [
+	"parent": "minecraft:block/block",
-    {"from":[0,0,1],"to":[16,1,15],"faces":{"up":{"texture":"#wood"},"down":{"texture":"#wood"},"north":{"texture":"#wood"},"south":{"texture":"#wood"},"east":{"texture":"#wood"},"west":{"texture":"#wood"}}},
+	"textures": {
-    {"from":[0,8,0],"to":[16,9,16],"faces":{"up":{"texture":"#wood"},"down":{"texture":"#wood"},"north":{"texture":"#wood"},"south":{"texture":"#wood"},"east":{"texture":"#wood"},"west":{"texture":"#wood"}}},
+		"2": "rivencraft:block/writing_desk",
-    {"from":[15,0,1],"to":[16,8,15],"faces":{"up":{"texture":"#wood"},"down":{"texture":"#wood"},"north":{"texture":"#wood"},"south":{"texture":"#wood"},"east":{"texture":"#wood"},"west":{"texture":"#wood"}}},
+		"particle": "rivencraft:block/writing_desk"
-    {"from":[0,3,1],"to":[15,4,15],"faces":{"up":{"texture":"#wood"},"down":{"texture":"#wood"},"north":{"texture":"#wood"},"south":{"texture":"#wood"},"east":{"texture":"#wood"},"west":{"texture":"#wood"}}},
+	},
-    {"from":[0,9,15],"to":[16,15,16],"faces":{"up":{"texture":"#wood"},"down":{"texture":"#wood"},"north":{"texture":"#wood"},"south":{"texture":"#wood"},"east":{"texture":"#wood"},"west":{"texture":"#wood"}}}
+	"elements": [
-  ]
+		{
+			"from": [1, 0, 1],
+			"to": [15, 1, 15],
+			"rotation": {"angle": 0, "axis": "y", "origin": [1, 0, 0]},
+			"faces": {
+				"north": {"uv": [1.8125, 4.125, 2.8125, 4.25], "texture": "#2"},
+				"east": {"uv": [0.21875, 11.88281, 1.04688, 12.88281], "texture": "#2"},
+				"south": {"uv": [1.53906, 10.5625, 2.63281, 11.5625], "texture": "#2"},
+				"west": {"uv": [0.14063, 10.5625, 1.17969, 11.5625], "texture": "#2"},
+				"up": {"uv": [1.8125, 4.125, 2.8125, 2.125], "texture": "#2"},
+				"down": {"uv": [4, 0, 5, 2], "texture": "#2"}
+			}
+		},
+		{
+			"from": [0, 11, 0],
+			"to": [16, 12, 16],
+			"rotation": {"angle": 0, "axis": "y", "origin": [0, 3, 0]},
+			"faces": {
+				"north": {"uv": [2, 2, 3, 2.125], "texture": "#2"},
+				"east": {"uv": [1, 0, 1.0625, 2], "rotation": 90, "texture": "#2"},
+				"south": {"uv": [3, 2, 4, 2.125], "texture": "#2"},
+				"west": {"uv": [2.8125, 4, 3.8125, 4.125], "texture": "#2"},
+				"up": {"uv": [2, 0, 3, 2], "texture": "#2"},
+				"down": {"uv": [9, 0, 10, 2], "texture": "#2"}
+			}
+		},
+		{
+			"from": [15, 0, 1],
+			"to": [16, 11, 15],
+			"faces": {
+				"north": {"uv": [7.6875, 2.625, 7.75, 4], "texture": "#2"},
+				"east": {"uv": [10.00156, 0.625, 11.00156, 2], "texture": "#2"},
+				"south": {"uv": [1.99219, 10.77344, 2.99219, 12.02344], "texture": "#2"},
+				"west": {"uv": [6.6875, 2.625, 7.6875, 4], "texture": "#2"},
+				"up": {"uv": [0.49219, 10.96094, 1.49219, 12.08594], "texture": "#2"},
+				"down": {"uv": [5.75313, 5.36719, 5.8125, 7.125], "texture": "#2"}
+			}
+		},
+		{
+			"from": [0, 0, 1],
+			"to": [1, 11, 15],
+			"rotation": {"angle": 0, "axis": "y", "origin": [-15, 0, 0]},
+			"faces": {
+				"north": {"uv": [7.68828, 2.625, 7.75078, 4], "texture": "#2"},
+				"east": {"uv": [7.6875, 2.62539, 6.6875, 4.00039], "texture": "#2"},
+				"south": {"uv": [0.05469, 12.22656, 1.05469, 13.32031], "texture": "#2"},
+				"west": {"uv": [3, 0, 4, 1.375], "texture": "#2"},
+				"up": {"uv": [0.15625, 10.83594, 1.15625, 11.97656], "texture": "#2"},
+				"down": {"uv": [7, 4.60156, 7.0625, 6.375], "texture": "#2"}
+			}
+		},
+		{
+			"from": [1, 5, 1],
+			"to": [15, 6, 15],
+			"rotation": {"angle": 0, "axis": "y", "origin": [1, 2, 0]},
+			"faces": {
+				"north": {"uv": [1.8125, 4.25, 2.8125, 4.125], "texture": "#2"},
+				"east": {"uv": [1.86719, 11.82813, 2.79688, 12.82813], "texture": "#2"},
+				"south": {"uv": [0.32813, 11.80469, 1.28906, 12.80469], "texture": "#2"},
+				"west": {"uv": [0.27344, 10.5625, 1.53125, 11.5625], "texture": "#2"},
+				"up": {"uv": [1.8125, 4.125, 2.8125, 2.125], "texture": "#2"},
+				"down": {"uv": [9, 0, 10, 2], "texture": "#2"}
+			}
+		},
+		{
+			"from": [0, 0, 15],
+			"to": [16, 11, 16],
+			"rotation": {"angle": 0, "axis": "y", "origin": [0, -9, 0]},
+			"faces": {
+				"north": {"uv": [9, 0.125, 10, 1.5], "texture": "#2"},
+				"east": {"uv": [10.8125, 0.625, 10.875, 2], "texture": "#2"},
+				"south": {"uv": [10.875, 0.625, 11.875, 2], "texture": "#2"},
+				"west": {"uv": [6.6875, 0.125, 6.75, 1.5], "texture": "#2"},
+				"up": {"uv": [0, 15, 16, 16], "texture": "#2"},
+				"down": {"uv": [2.8125, 4, 3.8125, 4.125], "texture": "#2"}
+			}
+		}
+	]
 }

src/main/resources/assets/rivencraft/models/item/book_binder.json

@@ -0,0 +1,3 @@
+{
+  "parent": "rivencraft:block/book_binder"
+}

src/main/resources/data/rivencraft/loot_table/blocks/book_binder.json

@@ -0,0 +1,4 @@
+{
+  "type": "minecraft:block",
+  "pools": [{"rolls":1,"entries":[{"type":"minecraft:item","name":"rivencraft:book_binder"}]}]
+}

src/main/resources/data/rivencraft/recipe/book_binder.json

@@ -0,0 +1,10 @@
+{
+  "type": "minecraft:crafting_shaped",
+  "category": "misc",
+  "pattern": ["III", "PPP", "P P"],
+  "key": {
+    "I": {"item":"minecraft:iron_ingot"},
+    "P": {"tag":"minecraft:planks"}
+  },
+  "result": {"id":"rivencraft:book_binder","count":1}
+}