chore(release): v0.1.17

package.json

@@ -1,7 +1,7 @@
 {
   "name": "margin-app",
   "private": true,
-  "version": "0.1.16",
+  "version": "0.1.17",
   "type": "module",
   "scripts": {
     "dev": "vite",

src-tauri/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "margin-app"
-version = "0.1.16"
+version = "0.1.17"
 description = "A Tauri App"
 authors = ["you"]
 edition = "2021"

src-tauri/src/gdrive.rs

@@ -15,6 +15,7 @@ use tauri::{Emitter, Manager};
 
 const FOLDER_NAME: &str = "margin";
 const DICTIONARY_NAME: &str = "custom-dictionary.txt";
+const DRIVE_SCOPE: &str = "https://www.googleapis.com/auth/drive.file";
 const SCOPES: &str = "openid email https://www.googleapis.com/auth/drive.file";
 const AUTH_TIMEOUT_SECS: u64 = 120;
 
@@ -58,6 +59,7 @@ pub struct Session {
     access_expiry: u64,
     email: Option<String>,
     folder_id: Option<String>,
+    scopes: Option<String>,
 }
 
 #[derive(Serialize, Deserialize, Default)]
@@ -68,6 +70,8 @@ struct BackupState {
     folder_id: Option<String>,
     last_backup: Option<u64>,
     #[serde(default)]
+    scopes: Option<String>,
+    #[serde(default)]
     files: HashMap<String, FileRecord>,
 }
 
@@ -84,6 +88,7 @@ pub struct Status {
     email: Option<String>,
     last_backup: Option<u64>,
     pending: bool,
+    needs_reauth: bool,
 }
 
 #[derive(Serialize)]
@@ -92,6 +97,15 @@ pub struct RestoreResult {
     restored: usize,
 }
 
+#[derive(Serialize)]
+#[serde(rename_all = "camelCase")]
+pub struct SyncOutcome {
+    uploaded: usize,
+    downloaded: usize,
+    #[serde(flatten)]
+    status: Status,
+}
+
 #[derive(Serialize)]
 #[serde(rename_all = "camelCase")]
 pub struct BackupOutcome {
@@ -164,6 +178,13 @@ fn urlencode(s: &str) -> String {
     url::form_urlencoded::byte_serialize(s.as_bytes()).collect()
 }
 
+fn has_drive_scope(scope: &str) -> bool {
+    scope.split_whitespace().any(|s| s == DRIVE_SCOPE)
+}
+
+const REAUTH_MESSAGE: &str =
+    "margin needs the \"See, edit, create and delete only the specific Google Drive files you use with this app\" permission. Connect again and tick that box.";
+
 fn drive_escape(s: &str) -> String {
     s.replace('\\', "\\\\").replace('\'', "\\'")
 }
@@ -260,6 +281,8 @@ struct TokenResponse {
     refresh_token: Option<String>,
     #[serde(default)]
     expires_in: u64,
+    #[serde(default)]
+    scope: Option<String>,
 }
 
 #[derive(Deserialize)]
@@ -484,7 +507,29 @@ async fn valid_access_token(app: &tauri::AppHandle, state: &GDriveState) -> Resu
     }
     let refresh = refresh.ok_or("Not connected to Google Drive.")?;
     let creds = load_credentials()?;
-    let tokens = refresh_access_token(&creds, &refresh).await?;
+    let tokens = match refresh_access_token(&creds, &refresh).await {
+        Ok(tokens) => tokens,
+        Err(e) => {
+            if e.contains("invalid_grant") {
+                forget_credentials(app, state);
+                return Err(
+                    "Google Drive access has expired. Connect again to keep backing up.".to_string()
+                );
+            }
+            return Err(e);
+        }
+    };
+    if let Some(granted) = &tokens.scope {
+        if !has_drive_scope(granted) {
+            let mut session = state.0.lock().unwrap();
+            session.scopes = Some(granted.clone());
+            drop(session);
+            let mut stored = load_state(app);
+            stored.scopes = Some(granted.clone());
+            let _ = save_state(app, &stored);
+            return Err(REAUTH_MESSAGE.to_string());
+        }
+    }
     let access_token = tokens.access_token.clone();
     {
         let mut session = state.0.lock().unwrap();
@@ -493,10 +538,18 @@ async fn valid_access_token(app: &tauri::AppHandle, state: &GDriveState) -> Resu
         if let Some(rotated) = &tokens.refresh_token {
             session.refresh_token = Some(rotated.clone());
         }
+        if let Some(granted) = &tokens.scope {
+            session.scopes = Some(granted.clone());
+        }
     }
-    if let Some(rotated) = &tokens.refresh_token {
+    if tokens.refresh_token.is_some() || tokens.scope.is_some() {
         let mut stored = load_state(app);
-        stored.refresh_token = Some(rotated.clone());
+        if let Some(rotated) = &tokens.refresh_token {
+            stored.refresh_token = Some(rotated.clone());
+        }
+        if let Some(granted) = &tokens.scope {
+            stored.scopes = Some(granted.clone());
+        }
         let _ = save_state(app, &stored);
     }
     Ok(access_token)
@@ -592,17 +645,19 @@ fn compute_pending(app: &tauri::AppHandle, stored: &BackupState) -> bool {
 }
 
 fn status_inner(app: &tauri::AppHandle, state: &GDriveState) -> Status {
-    let (connected, email) = {
+    let (connected, email, scopes) = {
         let session = state.0.lock().unwrap();
-        (session.refresh_token.is_some(), session.email.clone())
+        (session.refresh_token.is_some(), session.email.clone(), session.scopes.clone())
     };
     let stored = load_state(app);
     let pending = connected && compute_pending(app, &stored);
+    let granted = scopes.or_else(|| stored.scopes.clone());
     Status {
         connected,
         email: email.or(stored.email),
         last_backup: stored.last_backup,
         pending,
+        needs_reauth: connected && granted.map(|s| !has_drive_scope(&s)).unwrap_or(false),
     }
 }
 
@@ -613,6 +668,21 @@ pub fn init_session(app: &tauri::AppHandle) {
     session.refresh_token = stored.refresh_token;
     session.email = stored.email;
     session.folder_id = stored.folder_id;
+    session.scopes = stored.scopes;
+}
+
+fn forget_credentials(app: &tauri::AppHandle, state: &GDriveState) {
+    {
+        let mut session = state.0.lock().unwrap();
+        session.refresh_token = None;
+        session.access_token = None;
+        session.access_expiry = 0;
+        session.scopes = None;
+    }
+    let mut stored = load_state(app);
+    stored.refresh_token = None;
+    stored.scopes = None;
+    let _ = save_state(app, &stored);
 }
 
 async fn complete_auth(
@@ -631,6 +701,15 @@ async fn complete_auth(
     .map_err(|e| e.to_string())??;
 
     let tokens = exchange_code(&creds, &code, &redirect, &verifier).await?;
+    let granted = tokens.scope.clone().unwrap_or_default();
+    if !has_drive_scope(&granted) {
+        let _ = HTTP
+            .post("https://oauth2.googleapis.com/revoke")
+            .form(&[("token", tokens.access_token.as_str())])
+            .send()
+            .await;
+        return Err(REAUTH_MESSAGE.to_string());
+    }
     let email = fetch_email(&tokens.access_token).await?;
     let folder_id = ensure_folder(&tokens.access_token).await?;
 
@@ -644,6 +723,7 @@ async fn complete_auth(
         session.access_expiry = now() + tokens.expires_in.saturating_sub(60);
         session.email = Some(email.clone());
         session.folder_id = Some(folder_id.clone());
+        session.scopes = Some(granted.clone());
     }
 
     let mut stored = load_state(app);
@@ -652,6 +732,7 @@ async fn complete_auth(
     }
     stored.email = Some(email);
     stored.folder_id = Some(folder_id);
+    stored.scopes = Some(granted);
     save_state(app, &stored)?;
     Ok(())
 }
@@ -711,10 +792,12 @@ pub async fn gdrive_disconnect(app: tauri::AppHandle, state: tauri::State<'_, GD
         session.access_token = None;
         session.access_expiry = 0;
         session.email = None;
+        session.scopes = None;
     }
     let mut stored = load_state(&app);
     stored.refresh_token = None;
     stored.email = None;
+    stored.scopes = None;
     save_state(&app, &stored)?;
     Ok(status_inner(&app, &state))
 }
@@ -724,12 +807,13 @@ pub async fn gdrive_status(app: tauri::AppHandle, state: tauri::State<'_, GDrive
     Ok(status_inner(&app, &state))
 }
 
-#[tauri::command]
-pub async fn gdrive_backup(app: tauri::AppHandle, state: tauri::State<'_, GDriveState>) -> Result<BackupOutcome, String> {
-    let access_token = valid_access_token(&app, &state).await?;
-    let folder_id = ensure_folder_id(&app, &state, &access_token).await?;
-    let files = collect_local_files(&app)?;
-    let mut stored = load_state(&app);
+async fn push_local_files(
+    app: &tauri::AppHandle,
+    access_token: &str,
+    folder_id: &str,
+    stored: &mut BackupState,
+) -> Result<usize, String> {
+    let files = collect_local_files(app)?;
     let mut uploaded = 0;
     for (name, bytes) in &files {
         let hash = hash_bytes(bytes);
@@ -739,18 +823,27 @@ pub async fn gdrive_backup(app: tauri::AppHandle, state: tauri::State<'_, GDrive
                 continue;
             }
         }
-        let drive_id = match &existing {
-            Some(record) => Some(record.drive_id.clone()),
-            None => find_file(&access_token, &folder_id, name).await?.map(|file| file.id),
+        let drive_id = match existing.filter(|record| !record.drive_id.is_empty()) {
+            Some(record) => Some(record.drive_id),
+            None => find_file(access_token, folder_id, name).await?.map(|file| file.id),
         };
-        let result = upload_file(&access_token, &folder_id, name, bytes, drive_id).await?;
+        let result = upload_file(access_token, folder_id, name, bytes, drive_id).await?;
         stored.files.insert(name.clone(), FileRecord { hash, drive_id: result.id });
         uploaded += 1;
     }
+    Ok(uploaded)
+}
+
+#[tauri::command]
+pub async fn gdrive_backup(app: tauri::AppHandle, state: tauri::State<'_, GDriveState>) -> Result<BackupOutcome, String> {
+    let access_token = valid_access_token(&app, &state).await?;
+    let folder_id = ensure_folder_id(&app, &state, &access_token).await?;
+    let mut stored = load_state(&app);
+    let uploaded = push_local_files(&app, &access_token, &folder_id, &mut stored).await?;
     if uploaded > 0 {
         stored.last_backup = Some(now());
-        save_state(&app, &stored)?;
     }
+    save_state(&app, &stored)?;
     Ok(BackupOutcome {
         uploaded,
         status: Status {
@@ -758,6 +851,60 @@ pub async fn gdrive_backup(app: tauri::AppHandle, state: tauri::State<'_, GDrive
             email: stored.email.clone(),
             last_backup: stored.last_backup,
             pending: false,
+            needs_reauth: false,
+        },
+    })
+}
+
+#[tauri::command]
+pub async fn gdrive_sync(app: tauri::AppHandle, state: tauri::State<'_, GDriveState>) -> Result<SyncOutcome, String> {
+    let access_token = valid_access_token(&app, &state).await?;
+    let folder_id = ensure_folder_id(&app, &state, &access_token).await?;
+    let remote = list_in_folder(&access_token, &folder_id).await?;
+    let mut stored = load_state(&app);
+    let mut downloaded = 0;
+
+    for file in &remote {
+        let is_dictionary = file.name == DICTIONARY_NAME;
+        if !is_dictionary && !safe_book_name(&file.name) {
+            continue;
+        }
+        let destination = if is_dictionary {
+            dictionary_path(&app)?
+        } else {
+            crate::library::library_dir(&app)?.join(&file.name)
+        };
+        if destination.exists() {
+            let record = stored
+                .files
+                .entry(file.name.clone())
+                .or_insert_with(|| FileRecord { hash: String::new(), drive_id: file.id.clone() });
+            record.drive_id = file.id.clone();
+            continue;
+        }
+        let bytes = download_file(&access_token, &file.id).await?;
+        crate::project::atomic_write(&destination, &bytes, false)?;
+        stored.files.insert(
+            file.name.clone(),
+            FileRecord { hash: hash_bytes(&bytes), drive_id: file.id.clone() },
+        );
+        downloaded += 1;
+    }
+
+    let uploaded = push_local_files(&app, &access_token, &folder_id, &mut stored).await?;
+    if uploaded > 0 || downloaded > 0 {
+        stored.last_backup = Some(now());
+    }
+    save_state(&app, &stored)?;
+    Ok(SyncOutcome {
+        uploaded,
+        downloaded,
+        status: Status {
+            connected: true,
+            email: stored.email.clone(),
+            last_backup: stored.last_backup,
+            pending: false,
+            needs_reauth: false,
         },
     })
 }

src-tauri/src/lib.rs

@@ -97,6 +97,12 @@ fn build_menu<R: Runtime>(handle: &tauri::AppHandle<R>) -> tauri::Result<Menu<R>
             app_submenu.insert(&settings, 3)?;
             app_submenu.insert(&PredefinedMenuItem::separator(handle)?, 4)?;
         }
+        if let Some(window) = find_submenu("Window") {
+            let show_window = MenuItemBuilder::with_id("show-window", "Open Window")
+                .accelerator("CmdOrCtrl+Shift+M")
+                .build(handle)?;
+            window.append_items(&[&PredefinedMenuItem::separator(handle)?, &show_window])?;
+        }
         if let Some(view) = find_submenu("View") {
             let toggle_chapters = MenuItemBuilder::with_id("toggle-chapters", "Toggle Chapters")
                 .accelerator("CmdOrCtrl+\\")
@@ -177,10 +183,14 @@ pub fn run() {
                 ) {
                     app.emit("menu-action", event.id().0.as_str()).ok();
                 }
+                #[cfg(target_os = "macos")]
+                if event.id().0.as_str() == "show-window" {
+                    open_main_window(app);
+                }
             });
     }
 
-    builder
+    let app = builder
         .invoke_handler(tauri::generate_handler![
             epub::package_epub,
             epub::unzip_epub,
@@ -200,9 +210,36 @@ pub fn run() {
             gdrive::gdrive_disconnect,
             gdrive::gdrive_status,
             gdrive::gdrive_backup,
+            gdrive::gdrive_sync,
             gdrive::gdrive_restore,
             gdrive::gdrive_list_backups
         ])
-        .run(context)
-        .expect("error while running margin");
+        .build(context)
+        .expect("error while building margin");
+
+    app.run(|_app, _event| {
+        #[cfg(target_os = "macos")]
+        match &_event {
+            tauri::RunEvent::ExitRequested { code: None, api, .. } => api.prevent_exit(),
+            tauri::RunEvent::Reopen { has_visible_windows: false, .. } => open_main_window(_app),
+            _ => {}
+        }
+    });
+}
+
+#[cfg(target_os = "macos")]
+fn open_main_window(app: &tauri::AppHandle) {
+    use tauri::Manager;
+    if let Some(window) = app.get_webview_window("main") {
+        let _ = window.show();
+        let _ = window.unminimize();
+        let _ = window.set_focus();
+        return;
+    }
+    let Some(config) = app.config().app.windows.first().cloned() else {
+        return;
+    };
+    if let Ok(builder) = tauri::WebviewWindowBuilder::from_config(app, &config) {
+        let _ = builder.build();
+    }
 }

src-tauri/src/library.rs

@@ -120,6 +120,7 @@ pub fn list_books(app: tauri::AppHandle) -> Result<Vec<BookSummary>, String> {
             updated_at,
         });
     }
+    books.sort_by_key(|b| std::cmp::Reverse(b.updated_at));
     Ok(books)
 }
 

src-tauri/tauri.conf.json

@@ -1,7 +1,7 @@
 {
   "$schema": "https://schema.tauri.app/config/2",
   "productName": "Margin",
-  "version": "0.1.16",
+  "version": "0.1.17",
   "identifier": "studio.margin.app",
   "build": {
     "beforeDevCommand": "pnpm dev",

src/App.tsx

@@ -11,7 +11,7 @@ import { useBook } from "./store/useBook";
 import { useBackup } from "./store/useBackup";
 import { useExportPreview } from "./store/useExportPreview";
 import { isDesktop } from "./ipc";
-import { createAndOpenBook, saveBook } from "./library";
+import { createAndOpenBook, lastBookId, loadBook, saveBook } from "./library";
 import { runExport } from "./export/run";
 import { checkForUpdates } from "./updater";
 
@@ -51,12 +51,7 @@ function App() {
       if ((!book || !dirty) && !connected) return;
       event.preventDefault();
       if (book && dirty) await saveBook(book).catch(() => {});
-      if (connected) {
-        await Promise.race([
-          useBackup.getState().backup(true),
-          new Promise((resolve) => setTimeout(resolve, 8000)),
-        ]);
-      }
+      if (connected) useBackup.getState().backup(true);
       win.destroy();
     });
     return () => {
@@ -76,16 +71,34 @@ function App() {
 
   useEffect(() => {
     if (!isDesktop) return;
+    let first = true;
     const tick = async () => {
       await useBackup.getState().refresh();
       const state = useBackup.getState();
-      if (state.connected && state.pending) state.backup(true);
+      if (!state.connected || state.needsReauth) return;
+      if (first) {
+        first = false;
+        state.sync(true);
+      } else if (state.pending) {
+        state.backup(true);
+      }
     };
     tick();
     const id = setInterval(tick, 15 * 60 * 1000);
     return () => clearInterval(id);
   }, []);
 
+  useEffect(() => {
+    if (!isDesktop) return;
+    const id = lastBookId();
+    if (!id || useBook.getState().book) return;
+    loadBook(id)
+      .then((last) => {
+        if (!useBook.getState().book) useBook.getState().openBook(last);
+      })
+      .catch(() => {});
+  }, []);
+
   return (
     <>
       {book ? <EditorView /> : <Library onOpen={openBook} />}

src/backup.ts

@@ -6,6 +6,7 @@ export interface BackupStatus {
   email: string | null;
   lastBackup: number | null;
   pending: boolean;
+  needsReauth: boolean;
 }
 
 export interface RestoreResult {
@@ -16,11 +17,16 @@ export interface BackupOutcome extends BackupStatus {
   uploaded: number;
 }
 
+export interface SyncOutcome extends BackupStatus {
+  uploaded: number;
+  downloaded: number;
+}
+
 export interface RemoteBackup {
   name: string;
 }
 
-const OFFLINE: BackupStatus = { connected: false, email: null, lastBackup: null, pending: false };
+const OFFLINE: BackupStatus = { connected: false, email: null, lastBackup: null, pending: false, needsReauth: false };
 
 export async function gdriveStatus(): Promise<BackupStatus> {
   if (!isDesktop) return OFFLINE;
@@ -39,6 +45,10 @@ export async function gdriveBackup(): Promise<BackupOutcome> {
   return invoke<BackupOutcome>("gdrive_backup");
 }
 
+export async function gdriveSync(): Promise<SyncOutcome> {
+  return invoke<SyncOutcome>("gdrive_sync");
+}
+
 export async function gdriveRestore(): Promise<RestoreResult> {
   return invoke<RestoreResult>("gdrive_restore");
 }

src/components/AddPageMenu.tsx

@@ -1,6 +1,7 @@
 import { useEffect, useRef, useState } from "react";
 import { PAGE_TYPES } from "../model/book";
 import { useEscapeLayer } from "../escape";
+import { useFocusTrap } from "../focus";
 import { Icon } from "./Icon";
 
 interface AddPageMenuProps {
@@ -40,10 +41,7 @@ export function AddPageMenu({ onAdd, onAddPart }: AddPageMenuProps) {
     };
   }, [open]);
 
-  useEffect(() => {
-    if (!open) return;
-    popRef.current?.querySelector<HTMLElement>(".add-page-item")?.focus();
-  }, [open]);
+  useFocusTrap(popRef, open);
 
   useEscapeLayer(open, () => {
     setOpen(false);

src/components/BackupSettings.tsx

@@ -1,8 +1,9 @@
-import { useEffect, useState } from "react";
+import { useEffect, useRef, useState } from "react";
 import { Icon } from "./Icon";
 import { ConfirmDialog } from "./ConfirmDialog";
 import { useBackup } from "../store/useBackup";
 import { useEscapeLayer } from "../escape";
+import { useFocusTrap } from "../focus";
 import { formatBackupTime, gdriveListBackups } from "../backup";
 
 export function BackupSettings() {
@@ -12,10 +13,12 @@ export function BackupSettings() {
   const email = useBackup((s) => s.email);
   const lastBackup = useBackup((s) => s.lastBackup);
   const pending = useBackup((s) => s.pending);
+  const needsReauth = useBackup((s) => s.needsReauth);
   const phase = useBackup((s) => s.phase);
   const connect = useBackup((s) => s.connect);
   const disconnect = useBackup((s) => s.disconnect);
   const backup = useBackup((s) => s.backup);
+  const sync = useBackup((s) => s.sync);
   const restore = useBackup((s) => s.restore);
   const cancelConnect = useBackup((s) => s.cancelConnect);
   const openAuthUrl = useBackup((s) => s.openAuthUrl);
@@ -23,10 +26,13 @@ export function BackupSettings() {
 
   const [remoteCount, setRemoteCount] = useState<number | null>(null);
   const [confirmRestore, setConfirmRestore] = useState(false);
+  const panelRef = useRef<HTMLDivElement>(null);
   const working = phase === "working";
 
+  useFocusTrap(panelRef, open && !confirmRestore);
+
   useEffect(() => {
-    if (!open || !connected) {
+    if (!open || !connected || needsReauth) {
       setRemoteCount(null);
       return;
     }
@@ -37,7 +43,7 @@ export function BackupSettings() {
     return () => {
       active = false;
     };
-  }, [open, connected, lastBackup]);
+  }, [open, connected, needsReauth, lastBackup]);
 
   useEscapeLayer(open, close);
 
@@ -46,7 +52,7 @@ export function BackupSettings() {
   return (
     <>
       <div className="overlay" onClick={close}>
-        <div className="panel" onClick={(e) => e.stopPropagation()}>
+        <div ref={panelRef} className="panel" onClick={(e) => e.stopPropagation()}>
           <div className="panel-head">
             <h2>Backup &amp; Sync</h2>
             <button className="icon-btn" onClick={close} title="Close">
@@ -100,27 +106,51 @@ export function BackupSettings() {
                   </button>
                 </div>
 
-                <div className="backup-status-row">
-                  <span className={`backup-dot ${pending ? "is-pending" : "is-synced"}`} />
-                  <span>{pending ? "Changes not backed up" : formatBackupTime(lastBackup)}</span>
-                </div>
+                {needsReauth ? (
+                  <>
+                    <div className="backup-warn">
+                      margin can't reach your Drive folder. The permission to create and edit its own files was
+                      not granted, so nothing is being backed up.
+                    </div>
+                    <div className="backup-actions">
+                      <button className="btn-primary" disabled={working} onClick={connect}>
+                        {working ? "Working…" : "Reconnect Google Drive"}
+                      </button>
+                    </div>
+                    <p className="backup-note">
+                      On the Google screen, tick <strong>See, edit, create and delete only the specific Google Drive
+                      files you use with this app</strong> before continuing.
+                    </p>
+                  </>
+                ) : (
+                  <>
+                    <div className="backup-status-row">
+                      <span className={`backup-dot ${pending ? "is-pending" : "is-synced"}`} />
+                      <span>{pending ? "Changes not backed up" : formatBackupTime(lastBackup)}</span>
+                    </div>
 
-                <div className="backup-actions">
-                  <button className="btn-primary" disabled={working} onClick={() => backup()}>
-                    {working ? "Working…" : "Back up now"}
-                  </button>
-                  <button
-                    className="btn-ghost"
-                    disabled={working || remoteCount === 0}
-                    onClick={() => setConfirmRestore(true)}
-                  >
-                    {remoteCount === null ? "Restore from Drive" : `Restore ${remoteCount} book${remoteCount === 1 ? "" : "s"}`}
-                  </button>
-                </div>
+                    <div className="backup-actions">
+                      <button className="btn-primary" disabled={working} onClick={() => sync()}>
+                        {working ? "Working…" : "Sync now"}
+                      </button>
+                      <button className="btn-ghost" disabled={working} onClick={() => backup()}>
+                        Back up only
+                      </button>
+                      <button
+                        className="btn-ghost"
+                        disabled={working || remoteCount === 0}
+                        onClick={() => setConfirmRestore(true)}
+                      >
+                        {remoteCount === null ? "Restore from Drive" : `Restore ${remoteCount} book${remoteCount === 1 ? "" : "s"}`}
+                      </button>
+                    </div>
 
-                <p className="backup-note">
-                  Backs up automatically when you close margin, and every 15 minutes while there are changes.
-                </p>
+                    <p className="backup-note">
+                      Syncs on launch and right after connecting, backs up when you close margin, and every 15 minutes
+                      while there are changes.
+                    </p>
+                  </>
+                )}
               </>
             )}
           </div>

src/components/ConfirmDialog.tsx

@@ -1,5 +1,6 @@
 import { useEffect, useRef, type ReactNode } from "react";
 import { useEscapeLayer } from "../escape";
+import { useFocusTrap } from "../focus";
 import { Icon } from "./Icon";
 
 interface ConfirmDialogProps {
@@ -12,16 +13,18 @@ interface ConfirmDialogProps {
 
 export function ConfirmDialog({ title, message, confirmLabel = "Delete", onConfirm, onClose }: ConfirmDialogProps) {
   const confirmRef = useRef<HTMLButtonElement>(null);
+  const panelRef = useRef<HTMLDivElement>(null);
 
   useEffect(() => {
     confirmRef.current?.focus();
   }, []);
 
   useEscapeLayer(true, onClose);
+  useFocusTrap(panelRef);
 
   return (
     <div className="overlay" onClick={onClose}>
-      <div className="panel panel-confirm" onClick={(e) => e.stopPropagation()}>
+      <div ref={panelRef} className="panel panel-confirm" onClick={(e) => e.stopPropagation()}>
         <div className="panel-head">
           <h2>{title}</h2>
           <button className="icon-btn" onClick={onClose} title="Close">

src/components/EditorView.tsx

@@ -5,6 +5,7 @@ import { Sidebar } from "./Sidebar";
 import { Dock } from "./Dock";
 import { ResizeHandle } from "./ResizeHandle";
 import { Icon } from "./Icon";
+import { Menu } from "./Menu";
 import { Settings } from "./Settings";
 import { BackupButton } from "./BackupButton";
 import { CoverView } from "./CoverView";
@@ -23,6 +24,7 @@ import { WIDTH_OPTIONS } from "../width";
 import { bodyNumber, chapterKind, partNumber, partRoman } from "../model/book";
 import { saveBook } from "../library";
 import { useEscapeLayer } from "../escape";
+import { focusTrapped } from "../focus";
 import { isDesktop, runWritingTool } from "../ipc";
 import { useCompact } from "../useMedia";
 import { issueSignature, rememberWord, runProof } from "../proofing";
@@ -57,7 +59,7 @@ export function EditorView() {
   editorRef.current = editor;
   const lastChapterRef = useRef<string>("");
   const [sidebarOpen, setSidebarOpen] = useState(!isCompact);
-  const [dock, setDock] = useState(!isCompact);
+  const [dock, setDock] = useState(false);
   const [settingsOpen, setSettingsOpen] = useState(false);
   const [exportOpen, setExportOpen] = useState(false);
   const [moreOpen, setMoreOpen] = useState(false);
@@ -119,7 +121,7 @@ export function EditorView() {
   }, []);
 
   const focusEditorSoon = useCallback(() => {
-    if (useBook.getState().pendingTitleFocus) return;
+    if (useBook.getState().pendingTitleFocus || focusTrapped()) return;
     requestAnimationFrame(() => editorRef.current?.commands.focus(undefined, { scrollIntoView: false }));
   }, []);
 
@@ -162,6 +164,7 @@ export function EditorView() {
 
   useEffect(() => {
     const onKey = (e: KeyboardEvent) => {
+      if (focusTrapped()) return;
       if (e.metaKey && e.altKey && e.key.toLowerCase() === "f") {
         e.preventDefault();
         openFind(true);
@@ -214,7 +217,7 @@ export function EditorView() {
 
   useEffect(() => {
     setSidebarOpen(!isCompact);
-    setDock(!isCompact);
+    if (isCompact) setDock(false);
   }, [isCompact]);
 
   useEffect(() => {
@@ -305,25 +308,20 @@ export function EditorView() {
               <button className="icon-btn" data-on={widthOpen} onClick={() => setWidthOpen((v) => !v)} title="Editor width">
                 <Icon d="M3 5v14M21 5v14M7 12h10M7 12l3-3M7 12l3 3M17 12l-3-3M17 12l-3 3" />
               </button>
-              {widthOpen && (
-                <>
-                  <div className="menu-backdrop" onClick={() => setWidthOpen(false)} />
-                  <div className="menu">
-                    {WIDTH_OPTIONS.map((w) => (
-                      <button
-                        key={w.id}
-                        data-on={width === w.id}
-                        onClick={() => {
-                          setWidth(w.id);
-                          setWidthOpen(false);
-                        }}
-                      >
-                        {w.label}
-                      </button>
-                    ))}
-                  </div>
-                </>
-              )}
+              <Menu open={widthOpen} onClose={() => setWidthOpen(false)}>
+                {WIDTH_OPTIONS.map((w) => (
+                  <button
+                    key={w.id}
+                    data-on={width === w.id}
+                    onClick={() => {
+                      setWidth(w.id);
+                      setWidthOpen(false);
+                    }}
+                  >
+                    {w.label}
+                  </button>
+                ))}
+              </Menu>
             </div>
           )}
           {!isCompact && (
@@ -331,15 +329,10 @@ export function EditorView() {
               <button className="icon-btn" data-on={exportOpen} onClick={() => setExportOpen((v) => !v)} title="Export">
                 <Icon d="M5 13v6h14v-6M12 16V3M8 7l4-4 4 4" />
               </button>
-              {exportOpen && (
-                <>
-                  <div className="menu-backdrop" onClick={() => setExportOpen(false)} />
-                  <div className="menu">
-                    <button onClick={() => handleExport("pdf")}>Export PDF…</button>
-                    <button onClick={() => handleExport("epub")}>Export EPUB…</button>
-                  </div>
-                </>
-              )}
+              <Menu open={exportOpen} onClose={() => setExportOpen(false)}>
+                <button onClick={() => handleExport("pdf")}>Export PDF…</button>
+                <button onClick={() => handleExport("epub")}>Export EPUB…</button>
+              </Menu>
             </div>
           )}
           {!isCompact && (
@@ -362,56 +355,51 @@ export function EditorView() {
               <button className="icon-btn" data-on={moreOpen} onClick={() => setMoreOpen((v) => !v)} title="More" aria-label="More options">
                 <Icon d="M5 12h.01M12 12h.01M19 12h.01" />
               </button>
-              {moreOpen && (
-                <>
-                  <div className="menu-backdrop" onClick={() => setMoreOpen(false)} />
-                  <div className="menu">
-                    <div className="menu-label">Editor width</div>
-                    {WIDTH_OPTIONS.map((w) => (
-                      <button
-                        key={w.id}
-                        data-on={width === w.id}
-                        onClick={() => {
-                          setWidth(w.id);
-                          setMoreOpen(false);
-                        }}
-                      >
-                        {w.label}
-                      </button>
-                    ))}
+              <Menu open={moreOpen} onClose={() => setMoreOpen(false)}>
+                <div className="menu-label">Editor width</div>
+                {WIDTH_OPTIONS.map((w) => (
+                  <button
+                    key={w.id}
+                    data-on={width === w.id}
+                    onClick={() => {
+                      setWidth(w.id);
+                      setMoreOpen(false);
+                    }}
+                  >
+                    {w.label}
+                  </button>
+                ))}
+                <div className="menu-sep" />
+                <button
+                  onClick={() => {
+                    setMoreOpen(false);
+                    handleExport("pdf");
+                  }}
+                >
+                  Export PDF…
+                </button>
+                <button
+                  onClick={() => {
+                    setMoreOpen(false);
+                    handleExport("epub");
+                  }}
+                >
+                  Export EPUB…
+                </button>
+                {proofingAvailable && !coverActive && (
+                  <>
                     <div className="menu-sep" />
-                    <button
-                      onClick={() => {
-                        setMoreOpen(false);
-                        handleExport("pdf");
-                      }}
-                    >
-                      Export PDF…
+                    <button data-on={spelling} onClick={toggleSpelling}>
+                      Check spelling
                     </button>
-                    <button
-                      onClick={() => {
-                        setMoreOpen(false);
-                        handleExport("epub");
-                      }}
-                    >
-                      Export EPUB…
+                    <button data-on={grammar} onClick={toggleGrammar}>
+                      Check grammar
                     </button>
-                    {proofingAvailable && !coverActive && (
-                      <>
-                        <div className="menu-sep" />
-                        <button data-on={spelling} onClick={toggleSpelling}>
-                          Check spelling
-                        </button>
-                        <button data-on={grammar} onClick={toggleGrammar}>
-                          Check grammar
-                        </button>
-                      </>
-                    )}
-                    <div className="menu-sep" />
-                    <button onClick={toggleTheme}>{theme === "dark" ? "Light mode" : "Dark mode"}</button>
-                  </div>
-                </>
-              )}
+                  </>
+                )}
+                <div className="menu-sep" />
+                <button onClick={toggleTheme}>{theme === "dark" ? "Light mode" : "Dark mode"}</button>
+              </Menu>
             </div>
           )}
         </div>

src/components/ExportPreview.tsx

@@ -8,6 +8,7 @@ import { bookToPdfInputs, unsupportedScripts } from "../export/typst";
 import { compilePdf } from "../ipc";
 import { saveBytes } from "../project";
 import { useEscapeLayer } from "../escape";
+import { useFocusTrap } from "../focus";
 import { Icon } from "./Icon";
 
 pdfjs.GlobalWorkerOptions.workerSrc = workerUrl;
@@ -83,6 +84,7 @@ function ExportPreviewModal() {
   }, [book]);
 
   useEscapeLayer(true, close);
+  useFocusTrap(panelRef);
 
   useEffect(() => {
     const el = panelRef.current;
@@ -168,7 +170,7 @@ function ExportPreviewModal() {
             <button className="icon-btn" disabled={!pdf || zoom <= ZOOM_MIN} onClick={() => adjustZoom(-ZOOM_STEP)} title="Zoom out">
               <Icon d="M5 12h14" />
             </button>
-            {!compact && <span>{Math.round(zoom * 100)}%</span>}
+            {!compact && <span>{zoom === 1 ? "Fit" : `${Math.round(zoom * 100)}%`}</span>}
             <button className="icon-btn" disabled={!pdf || zoom >= ZOOM_MAX} onClick={() => adjustZoom(ZOOM_STEP)} title="Zoom in">
               <Icon d="M12 5v14M5 12h14" />
             </button>
@@ -207,7 +209,7 @@ function BookPages({ data, zoom, onPages }: { data: Uint8Array; zoom: number; on
   const stageRef = useRef<HTMLDivElement>(null);
   const [doc, setDoc] = useState<PDFDocumentProxy | null>(null);
   const [baseRatio, setBaseRatio] = useState<number | null>(null);
-  const [stageWidth, setStageWidth] = useState(0);
+  const [stage, setStage] = useState({ width: 0, height: 0 });
 
   useEffect(() => {
     let cancelled = false;
@@ -229,21 +231,21 @@ function BookPages({ data, zoom, onPages }: { data: Uint8Array; zoom: number; on
   }, [data, onPages]);
 
   useEffect(() => {
-    const stage = stageRef.current;
-    if (!stage) return;
-    const update = () => setStageWidth(stage.clientWidth);
+    const el = stageRef.current;
+    if (!el) return;
+    const update = () => setStage({ width: el.clientWidth, height: el.clientHeight });
     update();
     const observer = new ResizeObserver(update);
-    observer.observe(stage);
+    observer.observe(el);
     return () => observer.disconnect();
   }, [doc]);
 
-  const fit = Math.max(280, stageWidth - 56);
-  const displayWidth = Math.round(fit * zoom);
+  const pageFit = Math.max(240, Math.min(stage.width - 56, (stage.height - 56) / (baseRatio ?? 1)));
+  const displayWidth = Math.round(pageFit * zoom);
 
   return (
     <div className="preview-stage" ref={stageRef}>
-      {doc && baseRatio !== null && stageWidth > 0 && (
+      {doc && baseRatio !== null && stage.width > 0 && (
         <div className="preview-col">
           {Array.from({ length: doc.numPages }, (_, i) => (
             <PdfPage

src/components/FindBar.tsx

@@ -96,7 +96,12 @@ export function FindBar({ editor, open, initialExpanded, onClose }: FindBarProps
     };
   }, [editor, pendingNav, activeChapterId]);
 
-  useEscapeLayer(open, onClose);
+  const close = () => {
+    editor?.commands.focus();
+    onClose();
+  };
+
+  useEscapeLayer(open, close);
 
   if (!open || !editor) return null;
 
@@ -239,7 +244,7 @@ export function FindBar({ editor, open, initialExpanded, onClose }: FindBarProps
           <button className="find-toggle" data-on={wholeWord} title="Whole word" onClick={() => setWholeWord((v) => !v)}>
             <span className="find-ww">ab</span>
           </button>
-          <button className="find-btn" title="Close (Esc)" onClick={onClose}>
+          <button className="find-btn" title="Close (Esc)" onClick={close}>
             <Icon d="M18 6L6 18M6 6l12 12" size={14} />
           </button>
         </div>

src/components/Library.tsx

@@ -1,8 +1,19 @@
 import { useEffect, useState } from "react";
-import { type BookSummary, createAndOpenBook, deleteBook, exampleBook, listBooks, loadBook, saveBook } from "../library";
+import {
+  type BookSummary,
+  createAndOpenBook,
+  deleteBook,
+  exampleBook,
+  lastBookId,
+  listBooks,
+  loadBook,
+  rememberLastBook,
+  saveBook,
+} from "../library";
 import type { Book } from "../model/book";
 import { importEpub } from "../import/epub";
 import { clearPositions } from "../editor/positions";
+import { clearChapterStates } from "../editor/session";
 import { isDesktop } from "../ipc";
 import { ConfirmDialog } from "./ConfirmDialog";
 import { Icon } from "./Icon";
@@ -66,6 +77,8 @@ export function Library({ onOpen }: { onOpen: (book: Book) => void }) {
     if (!pendingDelete) return;
     await deleteBook(pendingDelete.id);
     clearPositions(pendingDelete.id);
+    clearChapterStates(pendingDelete.id);
+    if (lastBookId() === pendingDelete.id) rememberLastBook(null);
     setPendingDelete(null);
     refresh();
   };

src/components/Menu.tsx

@@ -0,0 +1,42 @@
+import { useRef, type ReactNode } from "react";
+import { useFocusTrap } from "../focus";
+
+interface MenuProps {
+  open: boolean;
+  onClose: () => void;
+  children: ReactNode;
+}
+
+export function Menu({ open, onClose, children }: MenuProps) {
+  const ref = useRef<HTMLDivElement>(null);
+
+  useFocusTrap(ref, open);
+
+  if (!open) return null;
+
+  const onKeyDown = (e: React.KeyboardEvent) => {
+    if (e.key !== "ArrowDown" && e.key !== "ArrowUp" && e.key !== "Home" && e.key !== "End") return;
+    e.preventDefault();
+    const items = Array.from(ref.current?.querySelectorAll<HTMLElement>("button") ?? []);
+    if (!items.length) return;
+    const at = items.indexOf(document.activeElement as HTMLElement);
+    const next =
+      e.key === "Home"
+        ? 0
+        : e.key === "End"
+          ? items.length - 1
+          : e.key === "ArrowDown"
+            ? (at + 1) % items.length
+            : (at - 1 + items.length) % items.length;
+    items[next]?.focus();
+  };
+
+  return (
+    <>
+      <div className="menu-backdrop" onClick={onClose} />
+      <div ref={ref} className="menu" onKeyDown={onKeyDown}>
+        {children}
+      </div>
+    </>
+  );
+}

src/components/MoveChapterDialog.tsx

@@ -0,0 +1,87 @@
+import { useEffect, useRef, useState } from "react";
+import type { Chapter } from "../model/book";
+import { type BookSummary, listBooks, moveChapterToBook, saveBook } from "../library";
+import { useBook } from "../store/useBook";
+import { useEscapeLayer } from "../escape";
+import { useFocusTrap } from "../focus";
+import { Icon } from "./Icon";
+
+interface MoveChapterDialogProps {
+  chapter: Chapter;
+  label: string;
+  onClose: () => void;
+}
+
+export function MoveChapterDialog({ chapter, label, onClose }: MoveChapterDialogProps) {
+  const bookId = useBook((s) => s.book?.id ?? "");
+  const deleteChapter = useBook((s) => s.deleteChapter);
+  const setNotice = useBook((s) => s.setNotice);
+  const [books, setBooks] = useState<BookSummary[] | null>(null);
+  const [moving, setMoving] = useState(false);
+  const panelRef = useRef<HTMLDivElement>(null);
+
+  useEscapeLayer(!moving, onClose);
+  useFocusTrap(panelRef, books !== null);
+
+  useEffect(() => {
+    listBooks()
+      .then((list) => setBooks(list.filter((b) => b.id !== bookId && !b.corrupt)))
+      .catch(() => setBooks([]));
+  }, [bookId]);
+
+  const move = async (target: BookSummary) => {
+    setMoving(true);
+    try {
+      const source = useBook.getState().book;
+      if (source) await saveBook(source);
+      await moveChapterToBook(chapter, target.id);
+      deleteChapter(chapter.id);
+      const trimmed = useBook.getState().book;
+      if (trimmed) await saveBook(trimmed);
+      setNotice(`Moved to ${target.title || "Untitled"}`);
+      onClose();
+    } catch (e) {
+      setNotice(`Could not move: ${e}`);
+      setMoving(false);
+    }
+  };
+
+  return (
+    <div className="overlay" onClick={moving ? undefined : onClose}>
+      <div ref={panelRef} className="panel panel-move" onClick={(e) => e.stopPropagation()}>
+        <div className="panel-head">
+          <h2>Move to book</h2>
+          <button className="icon-btn" onClick={onClose} title="Close">
+            <Icon d="M6 6l12 12M18 6L6 18" />
+          </button>
+        </div>
+        <div className="panel-body">
+          <p className="confirm-text">
+            Move <strong>{label}</strong> out of this book and into:
+          </p>
+          {books === null ? (
+            <p className="move-empty">Loading books…</p>
+          ) : books.length === 0 ? (
+            <p className="move-empty">There is no other book to move this into yet.</p>
+          ) : (
+            <ul className="move-list">
+              {books.map((b) => (
+                <li key={b.id}>
+                  <button className="move-target" disabled={moving} onClick={() => move(b)}>
+                    <span className="move-title">{b.title || "Untitled"}</span>
+                    {b.author && <span className="move-author">{b.author}</span>}
+                  </button>
+                </li>
+              ))}
+            </ul>
+          )}
+        </div>
+        <div className="panel-foot">
+          <button className="btn-ghost" onClick={onClose} disabled={moving}>
+            {moving ? "Moving…" : "Cancel"}
+          </button>
+        </div>
+      </div>
+    </div>
+  );
+}

src/components/ProofPopover.tsx

@@ -1,5 +1,6 @@
 import { useEffect, useRef } from "react";
 import { createPortal } from "react-dom";
+import { useFocusTrap } from "../focus";
 import { severityFor, type ProofCoords, type ProofIssue } from "../editor/proofing";
 
 function humanize(category: string): string {
@@ -20,6 +21,8 @@ const POP_WIDTH = 264;
 export function ProofPopover({ issue, coords, onReplace, onIgnore, onRemember, onClose }: ProofPopoverProps) {
   const popRef = useRef<HTMLDivElement>(null);
 
+  useFocusTrap(popRef);
+
   useEffect(() => {
     const onDown = (e: MouseEvent) => {
       if (popRef.current?.contains(e.target as Node)) return;

src/components/ResizeHandle.tsx

@@ -1,6 +1,8 @@
-import type { PointerEvent } from "react";
+import type { KeyboardEvent, PointerEvent } from "react";
 import { applyPaneWidth, currentPaneWidth, resetPaneWidth, type Pane } from "../panes";
 
+const STEP = 16;
+
 export function ResizeHandle({ pane }: { pane: Pane }) {
   const onPointerDown = (e: PointerEvent<HTMLDivElement>) => {
     e.preventDefault();
@@ -23,12 +25,26 @@ export function ResizeHandle({ pane }: { pane: Pane }) {
     handle.addEventListener("pointerup", onUp);
   };
 
+  const onKeyDown = (e: KeyboardEvent<HTMLDivElement>) => {
+    const towards = pane === "sidebar" ? 1 : -1;
+    if (e.key === "ArrowLeft" || e.key === "ArrowRight") {
+      e.preventDefault();
+      applyPaneWidth(pane, currentPaneWidth(pane) + (e.key === "ArrowRight" ? STEP : -STEP) * towards);
+    } else if (e.key === "Home" || e.key === "Enter") {
+      e.preventDefault();
+      resetPaneWidth(pane);
+    }
+  };
+
   return (
     <div
       className="pane-resizer"
       role="separator"
       aria-orientation="vertical"
+      aria-label={pane === "sidebar" ? "Resize chapters panel" : "Resize preview panel"}
+      tabIndex={0}
       onPointerDown={onPointerDown}
+      onKeyDown={onKeyDown}
       onDoubleClick={() => resetPaneWidth(pane)}
       title="Drag to resize · double-click to reset"
     />

src/components/RowMenu.tsx

@@ -1,11 +1,13 @@
 import { useEffect, useRef, useState } from "react";
 import { createPortal } from "react-dom";
 import { useEscapeLayer } from "../escape";
+import { useFocusTrap } from "../focus";
 import { Icon } from "./Icon";
 
 interface RowMenuProps {
   label: string;
   onDuplicate?: () => void;
+  onMove?: () => void;
   onDelete: () => void;
   onToggleTitle?: () => void;
   titleHidden?: boolean;
@@ -13,9 +15,10 @@ interface RowMenuProps {
   marginHidden?: boolean;
   onOpenChange?: (open: boolean) => void;
   className?: string;
+  tabIndex?: number;
 }
 
-export function RowMenu({ label, onDuplicate, onDelete, onToggleTitle, titleHidden, onToggleMargin, marginHidden, onOpenChange, className = "" }: RowMenuProps) {
+export function RowMenu({ label, onDuplicate, onMove, onDelete, onToggleTitle, titleHidden, onToggleMargin, marginHidden, onOpenChange, className = "", tabIndex }: RowMenuProps) {
   const [open, setOpen] = useState(false);
 
   useEffect(() => {
@@ -34,10 +37,7 @@ export function RowMenu({ label, onDuplicate, onDelete, onToggleTitle, titleHidd
     setOpen((v) => !v);
   };
 
-  useEffect(() => {
-    if (!open) return;
-    popRef.current?.querySelector<HTMLElement>(".row-menu-item")?.focus();
-  }, [open]);
+  useFocusTrap(popRef, open);
 
   useEscapeLayer(open, () => {
     setOpen(false);
@@ -89,6 +89,12 @@ export function RowMenu({ label, onDuplicate, onDelete, onToggleTitle, titleHidd
     onDuplicate?.();
   };
 
+  const moveOut = (e: React.MouseEvent) => {
+    e.stopPropagation();
+    setOpen(false);
+    onMove?.();
+  };
+
   const remove = (e: React.MouseEvent) => {
     e.stopPropagation();
     setOpen(false);
@@ -101,6 +107,7 @@ export function RowMenu({ label, onDuplicate, onDelete, onToggleTitle, titleHidd
         ref={btnRef}
         className={`row-menu-btn ${className}`}
         data-open={open}
+        tabIndex={tabIndex}
         title={label}
         onMouseDown={(e) => e.stopPropagation()}
         onClick={toggle}
@@ -136,6 +143,12 @@ export function RowMenu({ label, onDuplicate, onDelete, onToggleTitle, titleHidd
                 Duplicate
               </button>
             )}
+            {onMove && (
+              <button className="row-menu-item" onClick={moveOut}>
+                <Icon d="M4 12h13M13 8l4 4-4 4M20 4v16" size={14} />
+                Move to book…
+              </button>
+            )}
             <button className="row-menu-item danger" onClick={remove}>
               <Icon d="M5 7h14M10 7V5h4v2M7 7l1 13h8l1-13M10 11v6M14 11v6" size={14} />
               Delete

src/components/Settings.tsx

@@ -1,4 +1,4 @@
-import { useEffect, useState } from "react";
+import { useEffect, useRef, useState } from "react";
 import type { ReactNode } from "react";
 import { useBook } from "../store/useBook";
 import { listSystemFonts } from "../ipc";
@@ -14,6 +14,7 @@ import {
   pairingFor,
 } from "../model/fonts";
 import { useEscapeLayer } from "../escape";
+import { useFocusTrap } from "../focus";
 import { Icon } from "./Icon";
 
 const LANGUAGES = [
@@ -86,6 +87,13 @@ export function Settings({ onClose, onSave }: { onClose: () => void; onSave: ()
   }));
   const [system, setSystem] = useState<string[]>(() => systemFontCache ?? []);
   const [advanced, setAdvanced] = useState(() => pairingFor(draft.fonts) === null);
+  const panelRef = useRef<HTMLDivElement>(null);
+  const titleRef = useRef<HTMLInputElement>(null);
+
+  useEffect(() => {
+    titleRef.current?.focus();
+    titleRef.current?.select();
+  }, []);
 
   useEffect(() => {
     if (systemFontCache) return;
@@ -96,6 +104,7 @@ export function Settings({ onClose, onSave }: { onClose: () => void; onSave: ()
   }, []);
 
   useEscapeLayer(true, onClose);
+  useFocusTrap(panelRef);
 
   if (!book) return null;
 
@@ -115,7 +124,7 @@ export function Settings({ onClose, onSave }: { onClose: () => void; onSave: ()
 
   return (
     <div className="overlay" onClick={onClose}>
-      <div className="panel" onClick={(e) => e.stopPropagation()}>
+      <div ref={panelRef} className="panel" onClick={(e) => e.stopPropagation()}>
         <div className="panel-head">
           <h2>Book setup</h2>
           <button className="icon-btn" onClick={onClose} title="Close">
@@ -124,7 +133,7 @@ export function Settings({ onClose, onSave }: { onClose: () => void; onSave: ()
         </div>
         <div className="panel-body">
           <Field label="Title">
-            <input autoFocus value={draft.title} placeholder="Untitled" onChange={(e) => set({ title: e.target.value })} />
+            <input ref={titleRef} value={draft.title} placeholder="Untitled" onChange={(e) => set({ title: e.target.value })} />
           </Field>
           <Field label="Subtitle">
             <input value={draft.subtitle} onChange={(e) => set({ subtitle: e.target.value })} />

src/components/Sidebar.tsx

@@ -5,7 +5,9 @@ import { AddPageMenu } from "./AddPageMenu";
 import { ConfirmDialog } from "./ConfirmDialog";
 import { Icon } from "./Icon";
 import { RowMenu } from "./RowMenu";
+import { MoveChapterDialog } from "./MoveChapterDialog";
 import { relativeTime } from "../time";
+import { isDesktop } from "../ipc";
 
 interface Row {
   chapter: Chapter;
@@ -37,6 +39,7 @@ export function Sidebar({ onNavigate }: { onNavigate?: () => void }) {
   const [dragIndex, setDragIndex] = useState<number | null>(null);
   const [dropTarget, setDropTarget] = useState<DropTarget | null>(null);
   const [pendingDelete, setPendingDelete] = useState<{ id: string; title: string } | null>(null);
+  const [pendingMove, setPendingMove] = useState<{ chapter: Chapter; label: string } | null>(null);
   const [menuOpenId, setMenuOpenId] = useState<string | null>(null);
   const [now, setNow] = useState(() => Date.now());
 
@@ -142,6 +145,7 @@ export function Sidebar({ onNavigate }: { onNavigate?: () => void }) {
     });
 
   const onRowKeyDown = (e: React.KeyboardEvent, index: number, id: string) => {
+    if ((e.target as HTMLElement).closest(".row-menu-btn")) return;
     if (e.key === "Enter" || e.key === " ") {
       e.preventDefault();
       setActiveChapter(id);
@@ -240,6 +244,7 @@ export function Sidebar({ onNavigate }: { onNavigate?: () => void }) {
                     </span>
                     <RowMenu
                       label="Page options"
+                      tabIndex={row.chapter.id === tabStopId ? 0 : -1}
                       onOpenChange={(open) =>
                         setMenuOpenId((cur) => (open ? row.chapter.id : cur === row.chapter.id ? null : cur))
                       }
@@ -248,6 +253,7 @@ export function Sidebar({ onNavigate }: { onNavigate?: () => void }) {
                       marginHidden={!!row.chapter.noMargin}
                       onToggleMargin={() => setChapterNoMargin(row.chapter.id, !row.chapter.noMargin)}
                       onDuplicate={() => duplicateChapter(row.chapter.id)}
+                      onMove={isDesktop ? () => setPendingMove({ chapter: row.chapter, label: rowLabel }) : undefined}
                       onDelete={() => setPendingDelete({ id: row.chapter.id, title: rowLabel })}
                     />
                   </li>
@@ -276,6 +282,14 @@ export function Sidebar({ onNavigate }: { onNavigate?: () => void }) {
         )}
       </div>
 
+      {pendingMove && (
+        <MoveChapterDialog
+          chapter={pendingMove.chapter}
+          label={pendingMove.label}
+          onClose={() => setPendingMove(null)}
+        />
+      )}
+
       {pendingDelete && (
         <ConfirmDialog
           title="Delete"

src/components/UpdateDialog.tsx

@@ -1,6 +1,8 @@
+import { useRef } from "react";
 import { useUpdater } from "../store/useUpdater";
 import { installUpdate, dismissUpdate } from "../updater";
 import { useEscapeLayer } from "../escape";
+import { useFocusTrap } from "../focus";
 import { Icon } from "./Icon";
 
 const TITLES: Record<string, string> = {
@@ -21,7 +23,9 @@ export function UpdateDialog() {
   const error = useUpdater((s) => s.error);
 
   const busy = phase === "downloading" || phase === "installing";
+  const panelRef = useRef<HTMLDivElement>(null);
   useEscapeLayer(phase !== "idle" && !busy, dismissUpdate);
+  useFocusTrap(panelRef, phase !== "idle");
 
   if (phase === "idle") return null;
 
@@ -30,7 +34,7 @@ export function UpdateDialog() {
 
   return (
     <div className="overlay" onClick={close}>
-      <div className="panel panel-confirm" onClick={(e) => e.stopPropagation()}>
+      <div ref={panelRef} className="panel panel-confirm" onClick={(e) => e.stopPropagation()}>
         <div className="panel-head">
           <h2>{TITLES[phase]}</h2>
           {!busy && (

src/editor/Editor.tsx

@@ -1,9 +1,9 @@
-import { useEffect, useLayoutEffect, useRef } from "react";
-import { EditorContent, useEditor, type Editor as TiptapEditor } from "@tiptap/react";
+import { useEffect, useLayoutEffect, useRef, useState } from "react";
+import { EditorContent, type Editor as TiptapEditor } from "@tiptap/react";
 import { EditorState } from "@tiptap/pm/state";
 import type { JSONContent } from "@tiptap/core";
-import { editorExtensions } from "./extensions";
 import { loadPosition, savePosition, type ChapterPosition } from "./positions";
+import { loadChapterState, saveChapterState, sharedEditor, type ChapterState } from "./session";
 import { useBook } from "../store/useBook";
 
 interface EditorProps {
@@ -15,14 +15,6 @@ interface EditorProps {
   onContentError: (error: Error) => void;
 }
 
-interface Cached {
-  state: EditorState;
-  content: JSONContent;
-  scroll: number;
-}
-
-const SCROLL_KEEPOUT = { top: 32, right: 0, bottom: 96, left: 0 };
-
 function buildState(editor: TiptapEditor, content: JSONContent, onError: (error: Error) => void): EditorState {
   const base = editor.view.state;
   try {
@@ -35,31 +27,33 @@ function buildState(editor: TiptapEditor, content: JSONContent, onError: (error:
   }
 }
 
+function stillMatches(editor: TiptapEditor, entry: ChapterState, content: JSONContent): boolean {
+  if (entry.state.schema !== editor.schema) return false;
+  if (entry.content === content) return true;
+  try {
+    return entry.state.doc.eq(editor.schema.nodeFromJSON(content));
+  } catch {
+    return false;
+  }
+}
+
 export function Editor({ bookId, chapterId, content, onChange, onReady, onContentError }: EditorProps) {
   const onChangeRef = useRef(onChange);
   onChangeRef.current = onChange;
   const onContentErrorRef = useRef(onContentError);
   onContentErrorRef.current = onContentError;
 
-  const cache = useRef(new Map<string, Cached>());
-  const activeId = useRef(chapterId);
+  const [editor] = useState(() =>
+    sharedEditor({
+      onUpdate: (next) => onChangeRef.current(next),
+      onContentError: (error) => onContentErrorRef.current(error),
+    })
+  );
+
+  const active = useRef({ bookId: "", chapterId: "" });
   const latest = useRef<ChapterPosition | null>(null);
   const restoreToken = useRef(0);
 
-  const editor = useEditor({
-    extensions: editorExtensions,
-    content,
-    immediatelyRender: false,
-    enableContentCheck: true,
-    editorProps: {
-      attributes: { class: "prose" },
-      scrollThreshold: SCROLL_KEEPOUT,
-      scrollMargin: SCROLL_KEEPOUT,
-    },
-    onContentError: ({ error }) => onContentErrorRef.current(error),
-    onUpdate: ({ editor }) => onChangeRef.current(editor.getJSON()),
-  });
-
   const scrollerOf = (ed: TiptapEditor) => ed.view.dom.closest(".editor-pane") as HTMLElement | null;
 
   const restorePosition = (ed: TiptapEditor, id: string, focus: boolean) => {
@@ -82,62 +76,66 @@ export function Editor({ bookId, chapterId, content, onChange, onReady, onConten
     }
   };
 
-  const stash = (ed: TiptapEditor, id: string) => {
+  const stash = (ed: TiptapEditor) => {
+    const { bookId: prevBook, chapterId: prevChapter } = active.current;
+    if (!prevChapter) return;
     const scroller = scrollerOf(ed);
     const { from, to } = ed.state.selection;
-    const scroll = scroller?.scrollTop ?? 0;
-    const stored = useBook.getState().book?.chapters.find((c) => c.id === id)?.content ?? cache.current.get(id)?.content ?? ed.getJSON();
-    cache.current.set(id, { state: ed.view.state, content: stored, scroll });
-    savePosition(bookId, id, { from, to, scroll });
+    const scroll = scroller?.scrollTop ?? loadChapterState(prevBook, prevChapter)?.scroll ?? 0;
+    const stored = useBook.getState().book?.chapters.find((c) => c.id === prevChapter)?.content ?? ed.getJSON();
+    saveChapterState(prevBook, prevChapter, { state: ed.view.state, content: stored, scroll });
+    savePosition(prevBook, prevChapter, { from, to, scroll });
   };
 
+  const applyChapter = (ed: TiptapEditor, id: string, next: JSONContent, focus: boolean) => {
+    const entry = loadChapterState(bookId, id);
+    if (entry && stillMatches(ed, entry, next)) {
+      entry.content = next;
+      ed.view.updateState(entry.state);
+      const scroller = scrollerOf(ed);
+      if (scroller) scroller.scrollTop = entry.scroll;
+      ++restoreToken.current;
+      if (focus) ed.commands.focus(undefined, { scrollIntoView: false });
+      return;
+    }
+    ed.view.updateState(buildState(ed, next, onContentErrorRef.current));
+    saveChapterState(bookId, id, { state: ed.view.state, content: next, scroll: 0 });
+    restorePosition(ed, id, focus);
+  };
+
+  useLayoutEffect(() => {
+    const prev = active.current;
+    if (prev.bookId === bookId && prev.chapterId === chapterId) return;
+    stash(editor);
+    applyChapter(editor, chapterId, content, !prev.chapterId);
+    active.current = { bookId, chapterId };
+    latest.current = null;
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [bookId, chapterId, content, editor]);
+
   useEffect(() => {
-    if (!editor) return;
-    cache.current.set(chapterId, { state: editor.view.state, content, scroll: 0 });
-    activeId.current = chapterId;
-    restorePosition(editor, chapterId, true);
     onReady(editor);
-    return () => onReady(null);
+    return () => {
+      stash(editor);
+      onReady(null);
+    };
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [editor]);
 
-  useLayoutEffect(() => {
-    if (!editor) return;
-    const prev = activeId.current;
-    if (prev === chapterId) return;
-
-    stash(editor, prev);
-    const entry = cache.current.get(chapterId);
-    if (entry && entry.content === content) {
-      editor.view.updateState(entry.state);
-      const scroller = scrollerOf(editor);
-      if (scroller) scroller.scrollTop = entry.scroll;
-      ++restoreToken.current;
-    } else {
-      editor.view.updateState(buildState(editor, content, onContentErrorRef.current));
-      cache.current.set(chapterId, { state: editor.view.state, content, scroll: 0 });
-      restorePosition(editor, chapterId, false);
-    }
-    activeId.current = chapterId;
-    latest.current = null;
-    // eslint-disable-next-line react-hooks/exhaustive-deps
-  }, [chapterId, content, editor]);
-
   useEffect(() => {
-    if (!editor) return;
     const scroller = scrollerOf(editor);
     let timer: ReturnType<typeof setTimeout>;
     const capture = () => {
       const { from, to } = editor.state.selection;
       const scroll = scroller?.scrollTop ?? 0;
       latest.current = { from, to, scroll };
-      const entry = cache.current.get(activeId.current);
+      const entry = loadChapterState(active.current.bookId, active.current.chapterId);
       if (entry) entry.scroll = scroll;
     };
     const persist = () => {
       capture();
       clearTimeout(timer);
-      timer = setTimeout(() => savePosition(bookId, activeId.current, latest.current!), 400);
+      timer = setTimeout(() => savePosition(active.current.bookId, active.current.chapterId, latest.current!), 400);
     };
     editor.on("selectionUpdate", persist);
     scroller?.addEventListener("scroll", persist, { passive: true });
@@ -145,9 +143,9 @@ export function Editor({ bookId, chapterId, content, onChange, onReady, onConten
       clearTimeout(timer);
       editor.off("selectionUpdate", persist);
       scroller?.removeEventListener("scroll", persist);
-      if (latest.current) savePosition(bookId, activeId.current, latest.current);
+      if (latest.current) savePosition(active.current.bookId, active.current.chapterId, latest.current);
     };
-  }, [editor, bookId]);
+  }, [editor]);
 
   return <EditorContent editor={editor} className="editor-host" />;
 }

src/editor/FigureView.tsx

@@ -20,6 +20,14 @@ export function FigureView({ node, updateAttributes, selected }: NodeViewProps)
   const baseWidth = node.attrs.width ?? FIGURE_WIDTH[placement as FigurePlacement] ?? 100;
   const width = resizable ? (dragWidth ?? baseWidth) : null;
 
+  const nudge = (delta: number) => updateAttributes({ width: clampWidth((width ?? baseWidth) + delta) });
+
+  const onHandleKey = (e: React.KeyboardEvent) => {
+    if (e.key !== "ArrowLeft" && e.key !== "ArrowRight") return;
+    e.preventDefault();
+    nudge(e.key === "ArrowRight" ? 5 : -5);
+  };
+
   const startResize = (e: React.PointerEvent) => {
     e.preventDefault();
     const wrapper = frameRef.current?.closest(".figure") as HTMLElement | null;
@@ -52,7 +60,13 @@ export function FigureView({ node, updateAttributes, selected }: NodeViewProps)
       <div className="figure-frame" ref={frameRef}>
         {src ? <img src={src} alt={alt} /> : <div className="figure-empty">No image</div>}
         {selected && src && resizable && (
-          <div className="figure-handle" onPointerDown={startResize} title="Drag to resize" />
+          <button
+            className="figure-handle"
+            aria-label="Resize image"
+            title="Drag or press arrow keys to resize"
+            onPointerDown={startResize}
+            onKeyDown={onHandleKey}
+          />
         )}
       </div>
       <input

src/editor/FloatingToolbar.tsx

@@ -2,6 +2,7 @@ import { useEffect, useReducer, useRef, useState, type ReactNode } from "react";
 import type { Editor } from "@tiptap/react";
 import { Icon } from "../components/Icon";
 import { useEscapeLayer } from "../escape";
+import { useFocusTrap } from "../focus";
 import type { Alignment } from "./align";
 
 const ALIGN_ICONS: Record<Alignment, string> = {
@@ -28,7 +29,8 @@ function normalizeUrl(url: string): string {
 
 export function FloatingToolbar({ editor }: { editor: Editor | null }) {
   const fileRef = useRef<HTMLInputElement>(null);
-  const linkInputRef = useRef<HTMLInputElement>(null);
+  const linkPopRef = useRef<HTMLDivElement>(null);
+  const alignPopRef = useRef<HTMLDivElement>(null);
   const [linkOpen, setLinkOpen] = useState(false);
   const [linkValue, setLinkValue] = useState("");
   const [alignOpen, setAlignOpen] = useState(false);
@@ -40,9 +42,8 @@ export function FloatingToolbar({ editor }: { editor: Editor | null }) {
     setLinkOpen(true);
   };
 
-  useEffect(() => {
-    if (linkOpen) linkInputRef.current?.focus();
-  }, [linkOpen]);
+  useFocusTrap(linkPopRef, linkOpen);
+  useFocusTrap(alignPopRef, alignOpen);
 
   useEffect(() => {
     if (!editor) return;
@@ -130,7 +131,7 @@ export function FloatingToolbar({ editor }: { editor: Editor | null }) {
         {alignOpen && (
           <>
             <div className="link-pop-backdrop" onMouseDown={() => setAlignOpen(false)} />
-            <div className="align-pop" onMouseDown={(e) => e.stopPropagation()}>
+            <div ref={alignPopRef} className="align-pop" onMouseDown={(e) => e.stopPropagation()}>
               {(["left", "center", "right"] as Alignment[]).map((value) => (
                 <button
                   key={value}
@@ -153,9 +154,8 @@ export function FloatingToolbar({ editor }: { editor: Editor | null }) {
         {linkOpen && (
           <>
             <div className="link-pop-backdrop" onMouseDown={() => setLinkOpen(false)} />
-            <div className="link-pop" onMouseDown={(e) => e.stopPropagation()}>
+            <div ref={linkPopRef} className="link-pop" onMouseDown={(e) => e.stopPropagation()}>
               <input
-                ref={linkInputRef}
                 className="link-input"
                 value={linkValue}
                 placeholder="https://…"

src/editor/session.ts

@@ -0,0 +1,65 @@
+import { Editor as TiptapEditor } from "@tiptap/react";
+import type { JSONContent } from "@tiptap/core";
+import type { EditorState } from "@tiptap/pm/state";
+import { editorExtensions } from "./extensions";
+
+export interface ChapterState {
+  state: EditorState;
+  content: JSONContent;
+  scroll: number;
+}
+
+export interface EditorHooks {
+  onUpdate: (content: JSONContent) => void;
+  onContentError: (error: Error) => void;
+}
+
+const SCROLL_KEEPOUT = { top: 32, right: 0, bottom: 96, left: 0 };
+const MAX_STATES = 24;
+
+const states = new Map<string, ChapterState>();
+const stateKey = (bookId: string, chapterId: string) => `${bookId}:${chapterId}`;
+
+let instance: TiptapEditor | null = null;
+let hooks: EditorHooks | null = null;
+
+export function sharedEditor(next: EditorHooks): TiptapEditor {
+  hooks = next;
+  if (!instance) {
+    instance = new TiptapEditor({
+      extensions: editorExtensions,
+      enableContentCheck: true,
+      editorProps: {
+        attributes: { class: "prose" },
+        scrollThreshold: SCROLL_KEEPOUT,
+        scrollMargin: SCROLL_KEEPOUT,
+      },
+      onContentError: ({ error }) => hooks?.onContentError(error),
+      onUpdate: ({ editor }) => hooks?.onUpdate(editor.getJSON()),
+    });
+  }
+  return instance;
+}
+
+export function loadChapterState(bookId: string, chapterId: string): ChapterState | undefined {
+  return states.get(stateKey(bookId, chapterId));
+}
+
+export function saveChapterState(bookId: string, chapterId: string, entry: ChapterState): void {
+  for (const id of states.keys()) {
+    if (!id.startsWith(`${bookId}:`)) states.delete(id);
+  }
+  const id = stateKey(bookId, chapterId);
+  states.delete(id);
+  states.set(id, entry);
+  for (const oldest of states.keys()) {
+    if (states.size <= MAX_STATES) break;
+    states.delete(oldest);
+  }
+}
+
+export function clearChapterStates(bookId: string): void {
+  for (const id of states.keys()) {
+    if (id.startsWith(`${bookId}:`)) states.delete(id);
+  }
+}

src/focus.ts

@@ -0,0 +1,56 @@
+import { useEffect, useRef, type RefObject } from "react";
+
+const FOCUSABLE =
+  'a[href], button:not([disabled]), input:not([disabled]), select:not([disabled]), textarea:not([disabled]), [tabindex]:not([tabindex="-1"])';
+
+function focusable(root: HTMLElement): HTMLElement[] {
+  return Array.from(root.querySelectorAll<HTMLElement>(FOCUSABLE)).filter(
+    (el) => !el.hidden && el.offsetParent !== null,
+  );
+}
+
+let openTraps = 0;
+
+export function focusTrapped(): boolean {
+  return openTraps > 0;
+}
+
+export function useFocusTrap(ref: RefObject<HTMLElement | null>, active = true): void {
+  const opener = useRef<HTMLElement | null>(null);
+  const wasActive = useRef(false);
+  if (active && !wasActive.current) opener.current = document.activeElement as HTMLElement | null;
+  wasActive.current = active;
+
+  useEffect(() => {
+    const root = ref.current;
+    if (!active || !root) return;
+    openTraps++;
+    if (!root.contains(document.activeElement)) focusable(root)[0]?.focus();
+
+    const onKeyDown = (e: KeyboardEvent) => {
+      if (e.key !== "Tab") return;
+      const items = focusable(root);
+      if (!items.length) return;
+      const first = items[0];
+      const last = items[items.length - 1];
+      const current = document.activeElement as HTMLElement | null;
+      if (!current || !root.contains(current)) {
+        e.preventDefault();
+        (e.shiftKey ? last : first).focus();
+      } else if (e.shiftKey && current === first) {
+        e.preventDefault();
+        last.focus();
+      } else if (!e.shiftKey && current === last) {
+        e.preventDefault();
+        first.focus();
+      }
+    };
+
+    root.addEventListener("keydown", onKeyDown);
+    return () => {
+      openTraps--;
+      root.removeEventListener("keydown", onKeyDown);
+      if (opener.current?.isConnected) opener.current.focus();
+    };
+  }, [ref, active]);
+}

src/library.ts

@@ -1,6 +1,15 @@
 import { invoke } from "@tauri-apps/api/core";
 import { isDesktop } from "./ipc";
-import { type Book, SCHEMA_VERSION, createBook, schemaVersion, starterBook } from "./model/book";
+import {
+  type Book,
+  type Chapter,
+  SCHEMA_VERSION,
+  createBook,
+  insertByKind,
+  normalizeBook,
+  schemaVersion,
+  starterBook,
+} from "./model/book";
 
 export interface BookSummary {
   id: string;
@@ -39,6 +48,23 @@ export async function deleteBook(id: string): Promise<void> {
   await invoke("delete_book", { id });
 }
 
+export async function moveChapterToBook(chapter: Chapter, targetId: string): Promise<void> {
+  const target = normalizeBook(await loadBook(targetId));
+  const moved = { ...chapter, content: structuredClone(chapter.content), updatedAt: Date.now() };
+  await saveBook({ ...target, chapters: insertByKind(target.chapters, moved) });
+}
+
+const LAST_BOOK_KEY = "margin-last-book";
+
+export function lastBookId(): string | null {
+  return localStorage.getItem(LAST_BOOK_KEY);
+}
+
+export function rememberLastBook(id: string | null): void {
+  if (id) localStorage.setItem(LAST_BOOK_KEY, id);
+  else localStorage.removeItem(LAST_BOOK_KEY);
+}
+
 export function newBook(): Book {
   return createBook();
 }

src/model/book.ts

@@ -171,6 +171,19 @@ export function createPart(title = ""): Chapter {
   return { id: crypto.randomUUID(), title, content: emptyDoc(), kind: "part", updatedAt: Date.now() };
 }
 
+export function insertByKind(chapters: Chapter[], chapter: Chapter): Chapter[] {
+  const kind = chapterKind(chapter);
+  const next = [...chapters];
+  const at =
+    kind === "front"
+      ? next.filter((c) => chapterKind(c) === "front").length
+      : kind === "back"
+        ? next.length
+        : next.length - next.filter((c) => chapterKind(c) === "back").length;
+  next.splice(at, 0, chapter);
+  return next;
+}
+
 export function cloneChapter(chapter: Chapter): Chapter {
   const title = chapter.noTitle || !chapter.title ? chapter.title : `${chapter.title} (copy)`;
   return { ...chapter, id: crypto.randomUUID(), title, content: structuredClone(chapter.content), updatedAt: Date.now() };

src/store/useBackup.ts

@@ -7,6 +7,7 @@ import {
   gdriveDisconnect,
   gdriveRestore,
   gdriveStatus,
+  gdriveSync,
 } from "../backup";
 import { isDesktop } from "../ipc";
 import { useBook } from "./useBook";
@@ -18,6 +19,7 @@ interface BackupState {
   email: string | null;
   lastBackup: number | null;
   pending: boolean;
+  needsReauth: boolean;
   phase: Phase;
   error: string | null;
   authUrl: string | null;
@@ -33,6 +35,7 @@ interface BackupState {
   copyAuthUrl: () => Promise<void>;
   disconnect: () => Promise<void>;
   backup: (silent?: boolean) => Promise<void>;
+  sync: (silent?: boolean) => Promise<void>;
   restore: () => Promise<void>;
   restoreFromDrive: () => Promise<void>;
   openSettings: () => void;
@@ -43,11 +46,31 @@ function notify(message: string) {
   useBook.getState().setNotice(message);
 }
 
+const RECONNECT = /Connect again/;
+
+function describe(error: unknown, fallback: string): string {
+  const message = String(error).replace(/^Error:\s*/, "");
+  return RECONNECT.test(message) ? message : `${fallback}: ${message}`;
+}
+
+function plural(n: number, word: string): string {
+  return `${n} ${word}${n === 1 ? "" : "s"}`;
+}
+
+function syncMessage(uploaded: number, downloaded: number): string {
+  if (!uploaded && !downloaded) return "Everything is already in sync";
+  const parts = [];
+  if (downloaded) parts.push(`brought back ${plural(downloaded, "file")}`);
+  if (uploaded) parts.push(`backed up ${plural(uploaded, "file")}`);
+  return `Synced with Google Drive: ${parts.join(", ")}`;
+}
+
 export const useBackup = create<BackupState>((set, get) => ({
   connected: false,
   email: null,
   lastBackup: null,
   pending: false,
+  needsReauth: false,
   phase: "idle",
   error: null,
   authUrl: null,
@@ -60,6 +83,7 @@ export const useBackup = create<BackupState>((set, get) => ({
       email: status.email,
       lastBackup: status.lastBackup,
       pending: status.pending,
+      needsReauth: status.needsReauth,
     }),
   refresh: async () => {
     if (!isDesktop) return;
@@ -75,7 +99,7 @@ export const useBackup = create<BackupState>((set, get) => ({
         .then((url) => set({ authUrl: url }))
         .catch((e) => {
           set({ phase: "error", error: String(e), resolveConnect: null });
-          notify(`Could not connect: ${e}`);
+          notify(describe(e, "Could not connect"));
           resolve(false);
         });
     }),
@@ -91,11 +115,13 @@ export const useBackup = create<BackupState>((set, get) => ({
       await get().refresh();
       set({ phase: "idle", authUrl: null, error: null, resolveConnect: null });
       notify("Connected to Google Drive");
-    } else {
-      set({ phase: "error", authUrl: null, error: error ?? "authorization failed", resolveConnect: null });
-      notify(`Could not connect: ${error ?? "authorization failed"}`);
+      await get().sync();
+      resolve?.(true);
+      return;
     }
-    resolve?.(ok);
+    set({ phase: "error", authUrl: null, error: error ?? "authorization failed", resolveConnect: null });
+    notify(describe(error ?? "authorization failed", "Could not connect"));
+    resolve?.(false);
   },
   openAuthUrl: () => {
     const url = get().authUrl;
@@ -132,7 +158,22 @@ export const useBackup = create<BackupState>((set, get) => ({
       if (!silent) notify(outcome.uploaded > 0 ? "Backed up to Google Drive" : "Nothing new to back up");
     } catch (e) {
       set({ phase: "error", error: String(e) });
-      if (!silent) notify(`Backup failed: ${e}`);
+      await get().refresh();
+      if (!silent || RECONNECT.test(String(e))) notify(describe(e, "Backup failed"));
+    }
+  },
+  sync: async (silent = false) => {
+    if (!get().connected || get().phase === "working") return;
+    set({ phase: "working", error: null });
+    try {
+      const outcome = await gdriveSync();
+      get().apply(outcome);
+      set((s) => ({ phase: "idle", restoreNonce: outcome.downloaded > 0 ? s.restoreNonce + 1 : s.restoreNonce }));
+      if (!silent) notify(syncMessage(outcome.uploaded, outcome.downloaded));
+    } catch (e) {
+      set({ phase: "error", error: String(e) });
+      await get().refresh();
+      if (!silent || RECONNECT.test(String(e))) notify(describe(e, "Sync failed"));
     }
   },
   restore: async () => {
@@ -144,7 +185,8 @@ export const useBackup = create<BackupState>((set, get) => ({
       notify(result.restored > 0 ? `Restored ${result.restored} file${result.restored === 1 ? "" : "s"}` : "No backups found in Google Drive");
     } catch (e) {
       set({ phase: "error", error: String(e) });
-      notify(`Restore failed: ${e}`);
+      await get().refresh();
+      notify(describe(e, "Restore failed"));
     }
   },
   restoreFromDrive: async () => {

src/store/useBook.ts

@@ -14,7 +14,7 @@ import {
   normalizeBook,
 } from "../model/book";
 import { loadActiveChapter, saveActiveChapter } from "../editor/positions";
-import { saveBook } from "../library";
+import { rememberLastBook, saveBook } from "../library";
 import { applyBookFonts, resetBookFonts } from "../book-style";
 
 export const COVER_ID = "__cover__";
@@ -70,10 +70,12 @@ export const useBook = create<BookState>((set, get) => ({
     const valid = saved === COVER_ID || normalized.chapters.some((c) => c.id === saved);
     const activeChapterId = valid ? (saved as string) : normalized.chapters[0]?.id ?? "";
     applyBookFonts(normalized.settings.fonts);
+    rememberLastBook(normalized.id);
     set({ book: normalized, activeChapterId, dirty: false, pendingTitleFocus: null });
   },
   closeBook: () => {
     flushOutgoing(get().book, get().dirty);
+    rememberLastBook(null);
     resetBookFonts();
     set({ book: null, activeChapterId: "", dirty: false, pendingTitleFocus: null });
   },
@@ -163,6 +165,7 @@ export const useBook = create<BookState>((set, get) => ({
       const index = s.book.chapters.findIndex((c) => c.id === id);
       if (index === -1) return {};
       const chapters = s.book.chapters.filter((c) => c.id !== id);
+      if (!chapters.length) chapters.push(createChapter(""));
       const activeChapterId =
         s.activeChapterId === id ? (chapters[index] ?? chapters[index - 1])?.id ?? COVER_ID : s.activeChapterId;
       return { dirty: true, activeChapterId, book: { ...s.book, chapters } };

src/styles/app.css

@@ -169,6 +169,14 @@ body.resizing .pane-resizer::after {
   opacity: 0.55;
 }
 
+.pane-resizer:focus-visible {
+  outline: none;
+}
+
+.pane-resizer:focus-visible::after {
+  opacity: 1;
+}
+
 body.resizing {
   cursor: col-resize;
   user-select: none;
@@ -192,6 +200,7 @@ body.resizing {
   width: 0;
   border-right-width: 0;
   overflow: hidden;
+  visibility: hidden;
 }
 
 body.resizing .sidebar {
@@ -401,6 +410,7 @@ body.resizing .sidebar {
 }
 
 .chapter:hover .row-menu-btn,
+.chapter .row-menu-btn:focus-visible,
 .chapter .row-menu-btn[data-open="true"] {
   opacity: 0.7;
 }
@@ -1600,6 +1610,7 @@ body.resizing .sidebar {
 }
 
 .card-book:hover .card-menu,
+.card-menu:focus-visible,
 .card-menu[data-open="true"] {
   opacity: 1;
 }
@@ -1628,6 +1639,63 @@ body.resizing .sidebar {
   color: var(--ink);
 }
 
+.panel-move {
+  width: 440px;
+}
+
+.move-empty {
+  margin: 0;
+  font-size: var(--t-3);
+  color: var(--ink-soft);
+}
+
+.move-list {
+  display: flex;
+  flex-direction: column;
+  gap: 4px;
+  max-height: 300px;
+  overflow-y: auto;
+  margin: 0;
+  padding: 0;
+  list-style: none;
+}
+
+.move-target {
+  width: 100%;
+  display: flex;
+  flex-direction: column;
+  gap: 2px;
+  padding: 10px 12px;
+  border: 1px solid transparent;
+  border-radius: var(--r-sm);
+  background: none;
+  text-align: left;
+  cursor: pointer;
+}
+
+.move-target:hover:not(:disabled),
+.move-target:focus-visible {
+  background: var(--raised);
+  border-color: var(--line);
+}
+
+.move-target:disabled {
+  opacity: 0.5;
+  cursor: default;
+}
+
+.move-title {
+  font-family: var(--font-book);
+  font-size: var(--t-4);
+  color: var(--ink);
+}
+
+.move-author {
+  font-family: var(--font-ui);
+  font-size: var(--t-1);
+  color: var(--ink-soft);
+}
+
 .update-notes {
   max-height: 180px;
   overflow-y: auto;
@@ -2779,9 +2847,22 @@ body.resizing .sidebar {
 
 .backup-actions {
   display: flex;
+  flex-wrap: wrap;
   gap: 10px;
 }
 
+.backup-warn {
+  margin: 18px 0;
+  padding: 12px 14px;
+  border: 1px solid var(--line);
+  border-radius: var(--r-sm);
+  background: var(--raised);
+  font-family: var(--font-ui);
+  font-size: var(--t-3);
+  line-height: 1.5;
+  color: var(--ink-soft);
+}
+
 .backup-note {
   margin: 18px 0 0;
   color: var(--ink-faint);
@@ -2815,11 +2896,13 @@ body.resizing .sidebar {
   padding-left: env(safe-area-inset-left);
   border-right: 1px solid var(--line);
   transform: translateX(-100%);
-  transition: transform 260ms var(--ease);
+  visibility: hidden;
+  transition: transform 260ms var(--ease), visibility 260ms var(--ease);
 }
 
 .app[data-compact="true"][data-sidebar="true"] .sidebar {
   transform: translateX(0);
+  visibility: visible;
 }
 
 .app[data-compact="true"] .dock {