changes

src/App.tsx

@@ -6,6 +6,7 @@ import { useBook } from "./store/useBook";
 import { isDesktop } from "./ipc";
 import { newBook } from "./library";
 import { runExport } from "./export/run";
+import { checkForUpdates } from "./updater";
 
 function App() {
   const book = useBook((s) => s.book);
@@ -13,11 +14,13 @@ function App() {
 
   useEffect(() => {
     if (!isDesktop) return;
+    checkForUpdates(true);
     const unlisten = listen<string>("menu-action", (event) => {
       const state = useBook.getState();
       if (event.payload === "new-book") state.openBook(newBook());
       else if (event.payload === "export-pdf") runExport("pdf");
       else if (event.payload === "export-epub") runExport("epub");
+      else if (event.payload === "check-updates") checkForUpdates(false);
     });
     return () => {
       unlisten.then((stop) => stop());

src/components/Dock.tsx

@@ -133,7 +133,7 @@ function HtmlDock() {
       <div className="page">
         <div className="p-opener">
           <div className="p-num">{eyebrow}</div>
-          <div className="p-title">{chapter.title || "Untitled"}</div>
+          {!chapter.noTitle && <div className="p-title">{chapter.title || "Untitled"}</div>}
         </div>
         <div className="page-body" dangerouslySetInnerHTML={{ __html: html }} />
         <div className="folio">{idx * 8 + 7}</div>

src/components/EditorView.tsx

@@ -6,15 +6,20 @@ import { ResizeHandle } from "./ResizeHandle";
 import { Icon } from "./Icon";
 import { Settings } from "./Settings";
 import { CoverView } from "./CoverView";
+import { FindBar } from "./FindBar";
+import { ProofPopover } from "./ProofPopover";
 import { Editor } from "../editor/Editor";
 import { FloatingToolbar } from "../editor/FloatingToolbar";
+import type { ProofCoords, ProofIssue, ProofingStorage } from "../editor/proofing";
 import { COVER_ID, useBook } from "../store/useBook";
+import { useProofing } from "../store/useProofing";
 import { useTheme } from "../store/useTheme";
 import { useWidth } from "../store/useWidth";
 import { WIDTH_OPTIONS } from "../width";
 import { bodyNumber, chapterKind } from "../model/book";
 import { saveBook } from "../library";
 import { isDesktop } from "../ipc";
+import { issueSignature, rememberWord, runProof } from "../proofing";
 import { runExport } from "../export/run";
 
 export function EditorView() {
@@ -26,6 +31,7 @@ export function EditorView() {
   const setNotice = useBook((s) => s.setNotice);
   const setChapterContent = useBook((s) => s.setChapterContent);
   const setChapterTitle = useBook((s) => s.setChapterTitle);
+  const setChapterNoTitle = useBook((s) => s.setChapterNoTitle);
   const markSaved = useBook((s) => s.markSaved);
   const theme = useTheme((s) => s.theme);
   const toggleTheme = useTheme((s) => s.toggle);
@@ -37,6 +43,35 @@ export function EditorView() {
   const [settingsOpen, setSettingsOpen] = useState(false);
   const [exportOpen, setExportOpen] = useState(false);
   const [widthOpen, setWidthOpen] = useState(false);
+  const [findOpen, setFindOpen] = useState(false);
+  const [findExpanded, setFindExpanded] = useState(false);
+  const [proofPopover, setProofPopover] = useState<{ issue: ProofIssue; coords: ProofCoords } | null>(null);
+
+  const spelling = useProofing((s) => s.spelling);
+  const grammar = useProofing((s) => s.grammar);
+  const ignored = useProofing((s) => s.ignored);
+  const toggleSpelling = useProofing((s) => s.toggleSpelling);
+  const toggleGrammar = useProofing((s) => s.toggleGrammar);
+
+  const coverActive = activeChapterId === COVER_ID;
+  const proofingAvailable = isDesktop && book?.metadata.language === "en";
+
+  const openFind = useCallback((expanded: boolean) => {
+    setFindExpanded(expanded);
+    setFindOpen(true);
+  }, []);
+
+  const reproof = useCallback(() => {
+    if (!editor) return;
+    const state = useProofing.getState();
+    if (!proofingAvailable || (!state.spelling && !state.grammar)) {
+      editor.commands.clearProofIssues();
+      return;
+    }
+    runProof(editor.state.doc, { spelling: state.spelling, grammar: state.grammar }, state.ignored)
+      .then((issues) => editor.commands.setProofIssues(issues))
+      .catch(() => {});
+  }, [editor, proofingAvailable]);
 
   const saveNow = useCallback(() => {
     const current = useBook.getState().book;
@@ -54,11 +89,14 @@ export function EditorView() {
       if ((e.metaKey || e.ctrlKey) && e.key.toLowerCase() === "s") {
         e.preventDefault();
         saveNow();
+      } else if ((e.metaKey || e.ctrlKey) && e.key.toLowerCase() === "f") {
+        e.preventDefault();
+        openFind(e.altKey);
       }
     };
     window.addEventListener("keydown", onKey);
     return () => window.removeEventListener("keydown", onKey);
-  }, [saveNow]);
+  }, [saveNow, openFind]);
 
   useEffect(() => {
     if (!notice) return;
@@ -66,13 +104,45 @@ export function EditorView() {
     return () => clearTimeout(timer);
   }, [notice]);
 
+  useEffect(() => {
+    if (!editor) return;
+    const storage = (editor.storage as unknown as Record<string, ProofingStorage>).proofing;
+    storage.onClickIssue = (issue, coords) => setProofPopover({ issue, coords });
+    const closePopover = () => setProofPopover(null);
+    editor.on("update", closePopover);
+    return () => {
+      storage.onClickIssue = null;
+      editor.off("update", closePopover);
+    };
+  }, [editor]);
+
+  useEffect(() => {
+    if (!editor) return;
+    if (!proofingAvailable || coverActive || (!spelling && !grammar)) {
+      editor.commands.clearProofIssues();
+      return;
+    }
+    let timer: ReturnType<typeof setTimeout>;
+    const schedule = (delay: number) => {
+      clearTimeout(timer);
+      timer = setTimeout(reproof, delay);
+    };
+    editor.commands.clearProofIssues();
+    schedule(150);
+    const onUpdate = () => schedule(500);
+    editor.on("update", onUpdate);
+    return () => {
+      clearTimeout(timer);
+      editor.off("update", onUpdate);
+    };
+  }, [editor, spelling, grammar, ignored, activeChapterId, coverActive, proofingAvailable, reproof]);
+
   const handleExport = (format: "pdf" | "epub") => {
     setExportOpen(false);
     runExport(format);
   };
 
   if (!book) return null;
-  const coverActive = activeChapterId === COVER_ID;
   const idx = book.chapters.findIndex((c) => c.id === activeChapterId);
   const chapter = book.chapters[idx] ?? book.chapters[0];
   const realIdx = book.chapters.findIndex((c) => c.id === chapter?.id);
@@ -88,6 +158,19 @@ export function EditorView() {
           {dirty && <span className="dirty-dot" />}
         </button>
         <div className="actions">
+          <button className="icon-btn" data-on={findOpen} onClick={() => (findOpen ? setFindOpen(false) : openFind(false))} title="Find (⌘F)">
+            <Icon d="M11 4a7 7 0 1 0 0 14 7 7 0 0 0 0-14zM20 20l-4-4" />
+          </button>
+          {proofingAvailable && !coverActive && (
+            <>
+              <button className="icon-btn" data-on={spelling} onClick={toggleSpelling} title="Check spelling">
+                <Icon d="M4 17l4-10 4 10M5.4 13.4h5.2M15 17l2.5 2.5L22 14" />
+              </button>
+              <button className="icon-btn" data-on={grammar} onClick={toggleGrammar} title="Check grammar">
+                <Icon d="M4 7h16M4 12h12M4 17h7M13.5 18.5c1-1.2 2-1.2 3 0s2 1.2 3 0" />
+              </button>
+            </>
+          )}
           <div className="menu-wrap">
             <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" />
@@ -142,6 +225,13 @@ export function EditorView() {
         </div>
       </header>
 
+      <FindBar
+        editor={coverActive ? null : editor}
+        open={findOpen && !coverActive}
+        initialExpanded={findExpanded}
+        onClose={() => setFindOpen(false)}
+      />
+
       <div className="body">
         <Sidebar />
         <ResizeHandle pane="sidebar" />
@@ -155,11 +245,22 @@ export function EditorView() {
                   <div className="chapter-num">{eyebrow}</div>
                   <input
                     className="chapter-title-input"
-                    value={chapter.title}
-                    placeholder={kind === "body" ? "Chapter title" : "Page title"}
+                    value={chapter.noTitle ? "" : chapter.title}
+                    placeholder={chapter.noTitle ? "No title" : kind === "body" ? "Chapter title" : "Page title"}
                     spellCheck={false}
+                    disabled={chapter.noTitle}
                     onChange={(e) => setChapterTitle(chapter.id, e.target.value)}
                   />
+                  {(chapter.noTitle || !chapter.title.trim()) && (
+                    <label className="no-title-check">
+                      <input
+                        type="checkbox"
+                        checked={!!chapter.noTitle}
+                        onChange={(e) => setChapterNoTitle(chapter.id, e.target.checked)}
+                      />
+                      No title
+                    </label>
+                  )}
                 </header>
                 <Editor
                   chapterId={chapter.id}
@@ -176,6 +277,28 @@ export function EditorView() {
         {dock && <Dock />}
       </div>
 
+      {proofPopover && editor && (
+        <ProofPopover
+          issue={proofPopover.issue}
+          coords={proofPopover.coords}
+          onReplace={(suggestion) => {
+            const { from, to } = proofPopover.issue;
+            if (suggestion === "") editor.chain().focus().deleteRange({ from, to }).run();
+            else editor.chain().focus().insertContentAt({ from, to }, suggestion).run();
+            setProofPopover(null);
+          }}
+          onIgnore={() => {
+            useProofing.getState().ignore(issueSignature(proofPopover.issue));
+            setProofPopover(null);
+          }}
+          onRemember={() => {
+            rememberWord(proofPopover.issue.word).then(reproof).catch(() => {});
+            setProofPopover(null);
+          }}
+          onClose={() => setProofPopover(null)}
+        />
+      )}
+
       {settingsOpen && <Settings onClose={() => setSettingsOpen(false)} onSave={saveNow} />}
       {exporting && (
         <div className="export-overlay">

src/components/FindBar.tsx

@@ -0,0 +1,283 @@
+import { useEffect, useMemo, useRef, useState } from "react";
+import type { Editor as TiptapEditor } from "@tiptap/react";
+import { buildRegex, getSearchState } from "../editor/search";
+import { countMatches, replaceInContent } from "../search-book";
+import { useBook } from "../store/useBook";
+import { Icon } from "./Icon";
+
+interface FindBarProps {
+  editor: TiptapEditor | null;
+  open: boolean;
+  initialExpanded: boolean;
+  onClose: () => void;
+}
+
+type Scope = "chapter" | "book";
+type PendingNav = "first" | "last" | null;
+
+export function FindBar({ editor, open, initialExpanded, onClose }: FindBarProps) {
+  const book = useBook((s) => s.book);
+  const activeChapterId = useBook((s) => s.activeChapterId);
+  const setActiveChapter = useBook((s) => s.setActiveChapter);
+  const setChapterContent = useBook((s) => s.setChapterContent);
+  const setNotice = useBook((s) => s.setNotice);
+
+  const [query, setQuery] = useState("");
+  const [replacement, setReplacement] = useState("");
+  const [caseSensitive, setCaseSensitive] = useState(false);
+  const [wholeWord, setWholeWord] = useState(false);
+  const [expanded, setExpanded] = useState(initialExpanded);
+  const [scope, setScope] = useState<Scope>("chapter");
+  const [active, setActive] = useState({ count: 0, current0: 0 });
+  const [pendingNav, setPendingNav] = useState<PendingNav>(null);
+  const findInputRef = useRef<HTMLInputElement>(null);
+
+  const chapters = useMemo(() => book?.chapters ?? [], [book]);
+  const activeIdx = chapters.findIndex((c) => c.id === activeChapterId);
+  const options = { caseSensitive, wholeWord };
+
+  const jsonCounts = useMemo(() => {
+    const regex = query ? buildRegex(query, options) : null;
+    if (!regex) return chapters.map(() => 0);
+    return chapters.map((c) => countMatches(c.content, regex));
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [chapters, query, caseSensitive, wholeWord]);
+
+  useEffect(() => {
+    if (open) setExpanded(initialExpanded);
+  }, [open, initialExpanded]);
+
+  useEffect(() => {
+    if (!editor) return;
+    const update = () => {
+      const s = getSearchState(editor.state);
+      setActive({ count: s?.matches.length ?? 0, current0: s?.current ?? 0 });
+    };
+    editor.on("transaction", update);
+    update();
+    return () => {
+      editor.off("transaction", update);
+    };
+  }, [editor]);
+
+  useEffect(() => {
+    if (!editor) return;
+    if (open) {
+      editor.commands.setSearch(query, { caseSensitive, wholeWord });
+    } else {
+      editor.commands.clearSearch();
+    }
+  }, [editor, open, query, caseSensitive, wholeWord]);
+
+  useEffect(() => {
+    if (open) {
+      const input = findInputRef.current;
+      input?.focus();
+      input?.select();
+    }
+  }, [open]);
+
+  useEffect(() => {
+    if (!editor || !pendingNav) return;
+    let done = false;
+    const go = () => {
+      if (done) return;
+      done = true;
+      const s = getSearchState(editor.state);
+      if (s && s.matches.length) editor.commands.goToMatch(pendingNav === "first" ? 0 : s.matches.length - 1);
+      setPendingNav(null);
+    };
+    editor.on("transaction", go);
+    const raf = requestAnimationFrame(go);
+    return () => {
+      editor.off("transaction", go);
+      cancelAnimationFrame(raf);
+    };
+  }, [editor, pendingNav, activeChapterId]);
+
+  if (!open || !editor) return null;
+
+  const before = jsonCounts.slice(0, Math.max(0, activeIdx)).reduce((a, b) => a + b, 0);
+  const after = jsonCounts.slice(activeIdx + 1).reduce((a, b) => a + b, 0);
+  const total = before + active.count + after;
+  const globalCurrent = before + active.current0 + 1;
+  const otherHasMatches = chapters.some((c, i) => c.id !== activeChapterId && jsonCounts[i] > 0);
+
+  const countLabel = !query
+    ? ""
+    : total === 0
+    ? "No results"
+    : active.count === 0
+    ? `${total} found`
+    : `${globalCurrent} of ${total}`;
+
+  const nextChapterWith = (dir: 1 | -1): string | null => {
+    const n = chapters.length;
+    if (!n || activeIdx < 0) return null;
+    for (let step = 1; step <= n; step++) {
+      const i = (((activeIdx + dir * step) % n) + n) % n;
+      if (chapters[i].id !== activeChapterId && jsonCounts[i] > 0) return chapters[i].id;
+    }
+    return null;
+  };
+
+  const next = () => {
+    const s = getSearchState(editor.state);
+    const count = s?.matches.length ?? 0;
+    const cur = s?.current ?? 0;
+    if (count > 0 && cur < count - 1) {
+      editor.commands.findNext();
+      return;
+    }
+    if (otherHasMatches) {
+      const id = nextChapterWith(1);
+      if (id) {
+        setPendingNav("first");
+        setActiveChapter(id);
+        return;
+      }
+    }
+    editor.commands.findNext();
+  };
+
+  const prev = () => {
+    const s = getSearchState(editor.state);
+    const count = s?.matches.length ?? 0;
+    const cur = s?.current ?? 0;
+    if (count > 0 && cur > 0) {
+      editor.commands.findPrev();
+      return;
+    }
+    if (otherHasMatches) {
+      const id = nextChapterWith(-1);
+      if (id) {
+        setPendingNav("last");
+        setActiveChapter(id);
+        return;
+      }
+    }
+    editor.commands.findPrev();
+  };
+
+  const onFindKey = (e: React.KeyboardEvent) => {
+    if (e.key === "Enter") {
+      e.preventDefault();
+      e.shiftKey ? prev() : next();
+    } else if (e.key === "Escape") {
+      e.preventDefault();
+      onClose();
+    }
+  };
+
+  const replaceOne = () => {
+    editor.commands.replaceCurrent(replacement);
+    editor.commands.focus();
+  };
+
+  const replaceAll = () => {
+    if (scope === "chapter") {
+      editor.commands.replaceAllInChapter(replacement);
+      editor.commands.focus();
+      return;
+    }
+    const regex = buildRegex(query, options);
+    if (!regex) return;
+    let totalReplaced = 0;
+    let touched = 0;
+    const s = getSearchState(editor.state);
+    const activeCount = s?.matches.length ?? 0;
+    if (activeCount > 0) {
+      editor.commands.replaceAllInChapter(replacement);
+      totalReplaced += activeCount;
+      touched++;
+    }
+    for (const c of chapters) {
+      if (c.id === activeChapterId) continue;
+      const result = replaceInContent(c.content, regex, replacement);
+      if (result.count > 0) {
+        setChapterContent(c.id, result.content);
+        totalReplaced += result.count;
+        touched++;
+      }
+    }
+    setNotice(`Replaced ${totalReplaced} across ${touched} chapter${touched === 1 ? "" : "s"}`);
+    editor.commands.focus();
+  };
+
+  return (
+    <div className="find-bar glass">
+      <button
+        className="find-expand"
+        data-on={expanded}
+        title={expanded ? "Hide replace" : "Show replace"}
+        onClick={() => setExpanded((v) => !v)}
+      >
+        <Icon d={expanded ? "M6 9l6 6 6-6" : "M9 6l6 6-6 6"} size={14} />
+      </button>
+
+      <div className="find-stack">
+        <div className="find-row">
+          <input
+            ref={findInputRef}
+            className="find-input"
+            value={query}
+            placeholder="Find"
+            spellCheck={false}
+            onChange={(e) => setQuery(e.target.value)}
+            onKeyDown={onFindKey}
+          />
+          <span className="find-count">{countLabel}</span>
+          <button className="find-btn" title="Previous (⇧⏎)" disabled={!total} onClick={prev}>
+            <Icon d="M6 15l6-6 6 6" size={14} />
+          </button>
+          <button className="find-btn" title="Next (⏎)" disabled={!total} onClick={next}>
+            <Icon d="M6 9l6 6 6-6" size={14} />
+          </button>
+          <button className="find-toggle" data-on={caseSensitive} title="Match case" onClick={() => setCaseSensitive((v) => !v)}>
+            Aa
+          </button>
+          <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}>
+            <Icon d="M18 6L6 18M6 6l12 12" size={14} />
+          </button>
+        </div>
+
+        {expanded && (
+          <div className="find-row">
+            <input
+              className="find-input"
+              value={replacement}
+              placeholder="Replace"
+              spellCheck={false}
+              onChange={(e) => setReplacement(e.target.value)}
+              onKeyDown={(e) => {
+                if (e.key === "Enter") {
+                  e.preventDefault();
+                  replaceOne();
+                } else if (e.key === "Escape") {
+                  e.preventDefault();
+                  onClose();
+                }
+              }}
+            />
+            <button className="find-action" disabled={!active.count} onClick={replaceOne} title="Replace current match">
+              Replace
+            </button>
+            <button className="find-action" disabled={!total} onClick={replaceAll} title="Replace all matches">
+              Replace All
+            </button>
+            <button
+              className="find-scope"
+              title="Replace All scope"
+              onClick={() => setScope((s) => (s === "chapter" ? "book" : "chapter"))}
+            >
+              {scope === "chapter" ? "This chapter" : "Whole book"}
+            </button>
+          </div>
+        )}
+      </div>
+    </div>
+  );
+}

src/components/ProofPopover.tsx

@@ -0,0 +1,73 @@
+import { useEffect, useRef } from "react";
+import { createPortal } from "react-dom";
+import { severityFor, type ProofCoords, type ProofIssue } from "../editor/proofing";
+
+function humanize(category: string): string {
+  return category.replace(/([a-z])([A-Z])/g, "$1 $2");
+}
+
+interface ProofPopoverProps {
+  issue: ProofIssue;
+  coords: ProofCoords;
+  onReplace: (suggestion: string) => void;
+  onIgnore: () => void;
+  onRemember: () => void;
+  onClose: () => void;
+}
+
+const POP_WIDTH = 264;
+
+export function ProofPopover({ issue, coords, onReplace, onIgnore, onRemember, onClose }: ProofPopoverProps) {
+  const popRef = useRef<HTMLDivElement>(null);
+
+  useEffect(() => {
+    const onDown = (e: MouseEvent) => {
+      if (popRef.current?.contains(e.target as Node)) return;
+      onClose();
+    };
+    const close = () => onClose();
+    document.addEventListener("mousedown", onDown, true);
+    document.addEventListener("scroll", close, true);
+    window.addEventListener("resize", close);
+    return () => {
+      document.removeEventListener("mousedown", onDown, true);
+      document.removeEventListener("scroll", close, true);
+      window.removeEventListener("resize", close);
+    };
+  }, [onClose]);
+
+  const left = Math.min(Math.max(8, coords.left - POP_WIDTH / 2), window.innerWidth - POP_WIDTH - 8);
+  const top = coords.bottom + 6;
+
+  return createPortal(
+    <div
+      ref={popRef}
+      className="proof-pop"
+      style={{ left, top, width: POP_WIDTH }}
+      onMouseDown={(e) => e.stopPropagation()}
+    >
+      <div className={`proof-pop-kind sev-${severityFor(issue.category)}`}>{humanize(issue.category)}</div>
+      <div className="proof-pop-msg">{issue.message}</div>
+      {issue.suggestions.length > 0 && (
+        <div className="proof-pop-suggestions">
+          {issue.suggestions.map((suggestion, i) => (
+            <button key={i} className="proof-suggestion" onClick={() => onReplace(suggestion)}>
+              {suggestion === "" ? "Remove" : suggestion}
+            </button>
+          ))}
+        </div>
+      )}
+      <div className="proof-pop-actions">
+        <button className="proof-action" onClick={onIgnore}>
+          Ignore
+        </button>
+        {issue.kind === "spelling" && (
+          <button className="proof-action" onClick={onRemember}>
+            Remember
+          </button>
+        )}
+      </div>
+    </div>,
+    document.body
+  );
+}

src/components/RowMenu.tsx

@@ -4,11 +4,12 @@ import { Icon } from "./Icon";
 
 interface RowMenuProps {
   label: string;
+  onDuplicate?: () => void;
   onDelete: () => void;
   className?: string;
 }
 
-export function RowMenu({ label, onDelete, className = "" }: RowMenuProps) {
+export function RowMenu({ label, onDuplicate, onDelete, className = "" }: RowMenuProps) {
   const [open, setOpen] = useState(false);
   const [coords, setCoords] = useState({ top: 0, right: 0 });
   const btnRef = useRef<HTMLButtonElement>(null);
@@ -40,6 +41,12 @@ export function RowMenu({ label, onDelete, className = "" }: RowMenuProps) {
     };
   }, [open]);
 
+  const duplicate = (e: React.MouseEvent) => {
+    e.stopPropagation();
+    setOpen(false);
+    onDuplicate?.();
+  };
+
   const remove = (e: React.MouseEvent) => {
     e.stopPropagation();
     setOpen(false);
@@ -61,6 +68,12 @@ export function RowMenu({ label, onDelete, className = "" }: RowMenuProps) {
       {open &&
         createPortal(
           <div ref={popRef} className="row-menu-pop" style={{ top: coords.top, right: coords.right }}>
+            {onDuplicate && (
+              <button className="row-menu-item" onClick={duplicate}>
+                <Icon d="M9 9h11v11h-11z M6 15V5h9" size={14} />
+                Duplicate
+              </button>
+            )}
             <button className="row-menu-item danger" onClick={remove}>
               <Icon d="M5 7h14M10 7V5h4v2M7 7l1 13h8l1-13M10 11v6M14 11v6" size={14} />
               Delete

src/components/Sidebar.tsx

@@ -43,6 +43,7 @@ export function Sidebar() {
   const setActiveChapter = useBook((s) => s.setActiveChapter);
   const addChapter = useBook((s) => s.addChapter);
   const addPage = useBook((s) => s.addPage);
+  const duplicateChapter = useBook((s) => s.duplicateChapter);
   const deleteChapter = useBook((s) => s.deleteChapter);
   const moveChapter = useBook((s) => s.moveChapter);
   const closeBook = useBook((s) => s.closeBook);
@@ -195,6 +196,7 @@ export function Sidebar() {
                     </span>
                     <RowMenu
                       label="Page options"
+                      onDuplicate={() => duplicateChapter(row.chapter.id)}
                       onDelete={() => setPendingDelete({ id: row.chapter.id, title: row.chapter.title || "Untitled" })}
                     />
                   </li>

src/editor/FloatingToolbar.tsx

@@ -1,4 +1,4 @@
-import { useEffect, useRef, useState, type ReactNode } from "react";
+import { useEffect, useReducer, useRef, useState, type ReactNode } from "react";
 import type { Editor } from "@tiptap/react";
 import { Icon } from "../components/Icon";
 
@@ -23,11 +23,21 @@ export function FloatingToolbar({ editor }: { editor: Editor | null }) {
   const linkInputRef = useRef<HTMLInputElement>(null);
   const [linkOpen, setLinkOpen] = useState(false);
   const [linkValue, setLinkValue] = useState("");
+  const [, forceUpdate] = useReducer((x) => x + 1, 0);
 
   useEffect(() => {
     if (linkOpen) linkInputRef.current?.focus();
   }, [linkOpen]);
 
+  useEffect(() => {
+    if (!editor) return;
+    const update = () => forceUpdate();
+    editor.on("transaction", update);
+    return () => {
+      editor.off("transaction", update);
+    };
+  }, [editor]);
+
   if (!editor) return null;
 
   const insertImage = async (file: File) => {

src/editor/extensions.ts

@@ -3,6 +3,8 @@ import StarterKit from "@tiptap/starter-kit";
 import Placeholder from "@tiptap/extension-placeholder";
 import { Figure } from "./figure";
 import { ParagraphIndent } from "./indent";
+import { SearchHighlight } from "./search";
+import { Proofing } from "./proofing";
 
 export const editorExtensions: Extensions = [
   StarterKit.configure({
@@ -15,4 +17,6 @@ export const editorExtensions: Extensions = [
   }),
   Figure,
   ParagraphIndent,
+  SearchHighlight,
+  Proofing,
 ];

src/editor/proofing.ts

@@ -0,0 +1,133 @@
+import { Extension } from "@tiptap/core";
+import { Plugin, PluginKey } from "@tiptap/pm/state";
+import { Decoration, DecorationSet } from "@tiptap/pm/view";
+import type { Node as PMNode } from "@tiptap/pm/model";
+
+export interface ProofIssue {
+  from: number;
+  to: number;
+  kind: "spelling" | "grammar";
+  category: string;
+  message: string;
+  suggestions: string[];
+  word: string;
+}
+
+export type ProofSeverity = "error" | "warn" | "suggest";
+
+const WARN_CATEGORIES = new Set(["Redundancy", "Repetition", "Formatting", "Regionalism"]);
+const SUGGEST_CATEGORIES = new Set(["Style", "Readability", "Enhancement", "Miscellaneous"]);
+
+export function severityFor(category: string): ProofSeverity {
+  if (WARN_CATEGORIES.has(category)) return "warn";
+  if (SUGGEST_CATEGORIES.has(category)) return "suggest";
+  return "error";
+}
+
+export interface ProofCoords {
+  left: number;
+  top: number;
+  bottom: number;
+}
+
+interface ProofingState {
+  issues: ProofIssue[];
+  decorations: DecorationSet;
+}
+
+export const proofingKey = new PluginKey<ProofingState>("proofing");
+
+function buildDecorations(doc: PMNode, issues: ProofIssue[]): DecorationSet {
+  const size = doc.content.size;
+  const decos = issues
+    .filter((i) => i.from < i.to && i.to <= size)
+    .map((i) => Decoration.inline(i.from, i.to, { class: `proof-mark sev-${severityFor(i.category)}` }));
+  return DecorationSet.create(doc, decos);
+}
+
+declare module "@tiptap/core" {
+  interface Commands<ReturnType> {
+    proofing: {
+      setProofIssues: (issues: ProofIssue[]) => ReturnType;
+      clearProofIssues: () => ReturnType;
+    };
+  }
+}
+
+export interface ProofingStorage {
+  onClickIssue: ((issue: ProofIssue, coords: ProofCoords) => void) | null;
+}
+
+export const Proofing = Extension.create<unknown, ProofingStorage>({
+  name: "proofing",
+
+  addStorage() {
+    return { onClickIssue: null };
+  },
+
+  addProseMirrorPlugins() {
+    const storage = this.storage;
+    return [
+      new Plugin<ProofingState>({
+        key: proofingKey,
+        state: {
+          init: () => ({ issues: [], decorations: DecorationSet.empty }),
+          apply(tr, value, _old, newState) {
+            const meta = tr.getMeta(proofingKey) as { issues: ProofIssue[] } | { clear: true } | undefined;
+            if (meta && "issues" in meta) {
+              return { issues: meta.issues, decorations: buildDecorations(newState.doc, meta.issues) };
+            }
+            if (meta && "clear" in meta) {
+              return { issues: [], decorations: DecorationSet.empty };
+            }
+            if (tr.docChanged && value.issues.length) {
+              const issues = value.issues
+                .map((i) => ({ ...i, from: tr.mapping.map(i.from), to: tr.mapping.map(i.to) }))
+                .filter((i) => i.to > i.from);
+              return { issues, decorations: value.decorations.map(tr.mapping, tr.doc) };
+            }
+            return value;
+          },
+        },
+        props: {
+          decorations(state) {
+            return proofingKey.getState(state)?.decorations ?? DecorationSet.empty;
+          },
+          handleClick(view, pos) {
+            const s = proofingKey.getState(view.state);
+            if (!s || !s.issues.length) return false;
+            const hits = s.issues.filter((i) => pos >= i.from && pos <= i.to);
+            if (!hits.length) return false;
+            const issue = hits.find((i) => i.kind === "spelling") ?? hits[0];
+            if (!storage.onClickIssue) return false;
+            const start = view.coordsAtPos(issue.from);
+            const end = view.coordsAtPos(issue.to);
+            storage.onClickIssue(issue, {
+              left: (start.left + end.left) / 2,
+              top: start.top,
+              bottom: end.bottom,
+            });
+            return false;
+          },
+        },
+      }),
+    ];
+  },
+
+  addCommands() {
+    return {
+      setProofIssues:
+        (issues) =>
+        ({ tr, dispatch }) => {
+          if (dispatch) dispatch(tr.setMeta(proofingKey, { issues }));
+          return true;
+        },
+      clearProofIssues:
+        () =>
+        ({ tr, dispatch }) => {
+          if (dispatch) dispatch(tr.setMeta(proofingKey, { clear: true }));
+          return true;
+        },
+    };
+  },
+});

src/editor/search.ts

@@ -0,0 +1,233 @@
+import { Extension } from "@tiptap/core";
+import { Plugin, PluginKey } from "@tiptap/pm/state";
+import { Decoration, DecorationSet, type EditorView } from "@tiptap/pm/view";
+import type { Node as PMNode } from "@tiptap/pm/model";
+
+export interface SearchOptions {
+  caseSensitive: boolean;
+  wholeWord: boolean;
+}
+
+export interface SearchMatch {
+  from: number;
+  to: number;
+}
+
+interface SearchState {
+  query: string;
+  options: SearchOptions;
+  matches: SearchMatch[];
+  current: number;
+  decorations: DecorationSet;
+}
+
+export const searchKey = new PluginKey<SearchState>("search");
+
+const EMPTY: SearchState = {
+  query: "",
+  options: { caseSensitive: false, wholeWord: false },
+  matches: [],
+  current: 0,
+  decorations: DecorationSet.empty,
+};
+
+function escapeRegExp(text: string): string {
+  return text.replace(/[.*+?^${}()|[\]\\]/g, "\\$&");
+}
+
+export function buildRegex(query: string, options: SearchOptions): RegExp | null {
+  if (!query) return null;
+  let pattern = escapeRegExp(query);
+  if (options.wholeWord) pattern = `\\b${pattern}\\b`;
+  try {
+    return new RegExp(pattern, options.caseSensitive ? "g" : "gi");
+  } catch {
+    return null;
+  }
+}
+
+export function findMatches(doc: PMNode, regex: RegExp): SearchMatch[] {
+  const matches: SearchMatch[] = [];
+  let runText = "";
+  let runStart = 0;
+  const flush = () => {
+    if (!runText) return;
+    regex.lastIndex = 0;
+    let m: RegExpExecArray | null;
+    while ((m = regex.exec(runText)) !== null) {
+      const from = runStart + m.index;
+      matches.push({ from, to: from + m[0].length });
+      if (m.index === regex.lastIndex) regex.lastIndex++;
+    }
+    runText = "";
+  };
+  doc.descendants((node, pos) => {
+    if (node.isText) {
+      if (!runText) runStart = pos;
+      runText += node.text ?? "";
+    } else {
+      flush();
+    }
+    return true;
+  });
+  flush();
+  return matches;
+}
+
+function buildDecorations(doc: PMNode, matches: SearchMatch[], current: number): DecorationSet {
+  if (!matches.length) return DecorationSet.empty;
+  const decos = matches.map((m, i) =>
+    Decoration.inline(m.from, m.to, {
+      class: i === current ? "search-match search-match-current" : "search-match",
+    })
+  );
+  return DecorationSet.create(doc, decos);
+}
+
+function recompute(doc: PMNode, query: string, options: SearchOptions, desiredCurrent: number): SearchState {
+  const regex = buildRegex(query, options);
+  if (!regex) return { ...EMPTY, query, options };
+  const matches = findMatches(doc, regex);
+  const current = matches.length ? Math.max(0, Math.min(desiredCurrent, matches.length - 1)) : 0;
+  return { query, options, matches, current, decorations: buildDecorations(doc, matches, current) };
+}
+
+function scrollMatchIntoView(view: EditorView, match: SearchMatch) {
+  const { node } = view.domAtPos(match.from);
+  const el = node.nodeType === Node.TEXT_NODE ? (node as Text).parentElement : (node as HTMLElement);
+  el?.scrollIntoView({ block: "center", behavior: "smooth" });
+}
+
+export function getSearchState(state: { plugins: unknown } | unknown): SearchState | undefined {
+  return searchKey.getState(state as never);
+}
+
+declare module "@tiptap/core" {
+  interface Commands<ReturnType> {
+    search: {
+      setSearch: (query: string, options: SearchOptions) => ReturnType;
+      clearSearch: () => ReturnType;
+      findNext: () => ReturnType;
+      findPrev: () => ReturnType;
+      goToMatch: (index: number) => ReturnType;
+      replaceCurrent: (replacement: string) => ReturnType;
+      replaceAllInChapter: (replacement: string) => ReturnType;
+    };
+  }
+}
+
+export const SearchHighlight = Extension.create({
+  name: "searchHighlight",
+
+  addProseMirrorPlugins() {
+    return [
+      new Plugin<SearchState>({
+        key: searchKey,
+        state: {
+          init: () => EMPTY,
+          apply(tr, value, _old, newState) {
+            const meta = tr.getMeta(searchKey) as
+              | { type: "search"; query: string; options: SearchOptions }
+              | { type: "nav"; current: number }
+              | { type: "clear" }
+              | undefined;
+            if (meta?.type === "search") {
+              return recompute(newState.doc, meta.query, meta.options, 0);
+            }
+            if (meta?.type === "nav" && value.matches.length) {
+              const current = ((meta.current % value.matches.length) + value.matches.length) % value.matches.length;
+              return { ...value, current, decorations: buildDecorations(newState.doc, value.matches, current) };
+            }
+            if (meta?.type === "clear") {
+              return { ...EMPTY };
+            }
+            if (tr.docChanged && value.query) {
+              return recompute(newState.doc, value.query, value.options, value.current);
+            }
+            return value;
+          },
+        },
+        props: {
+          decorations(state) {
+            return searchKey.getState(state)?.decorations ?? DecorationSet.empty;
+          },
+        },
+      }),
+    ];
+  },
+
+  addCommands() {
+    return {
+      setSearch:
+        (query, options) =>
+        ({ tr, dispatch }) => {
+          if (dispatch) dispatch(tr.setMeta(searchKey, { type: "search", query, options }));
+          return true;
+        },
+      clearSearch:
+        () =>
+        ({ tr, dispatch }) => {
+          if (dispatch) dispatch(tr.setMeta(searchKey, { type: "clear" }));
+          return true;
+        },
+      findNext:
+        () =>
+        ({ state, dispatch, view, tr }) => {
+          const s = searchKey.getState(state);
+          if (!s || !s.matches.length) return false;
+          const current = (s.current + 1) % s.matches.length;
+          if (dispatch) dispatch(tr.setMeta(searchKey, { type: "nav", current }));
+          scrollMatchIntoView(view, s.matches[current]);
+          return true;
+        },
+      findPrev:
+        () =>
+        ({ state, dispatch, view, tr }) => {
+          const s = searchKey.getState(state);
+          if (!s || !s.matches.length) return false;
+          const current = (s.current - 1 + s.matches.length) % s.matches.length;
+          if (dispatch) dispatch(tr.setMeta(searchKey, { type: "nav", current }));
+          scrollMatchIntoView(view, s.matches[current]);
+          return true;
+        },
+      goToMatch:
+        (index) =>
+        ({ state, dispatch, view, tr }) => {
+          const s = searchKey.getState(state);
+          if (!s || !s.matches.length) return false;
+          const current = ((index % s.matches.length) + s.matches.length) % s.matches.length;
+          if (dispatch) dispatch(tr.setMeta(searchKey, { type: "nav", current }));
+          scrollMatchIntoView(view, s.matches[current]);
+          return true;
+        },
+      replaceCurrent:
+        (replacement) =>
+        ({ state, dispatch, view, tr }) => {
+          const s = searchKey.getState(state);
+          if (!s || !s.matches.length) return false;
+          const m = s.matches[s.current];
+          if (dispatch) {
+            tr.insertText(replacement, m.from, m.to);
+            dispatch(tr);
+            const ns = searchKey.getState(view.state);
+            if (ns && ns.matches.length) scrollMatchIntoView(view, ns.matches[ns.current]);
+          }
+          return true;
+        },
+      replaceAllInChapter:
+        (replacement) =>
+        ({ state, dispatch, tr }) => {
+          const s = searchKey.getState(state);
+          if (!s || !s.matches.length) return false;
+          if (dispatch) {
+            for (let i = s.matches.length - 1; i >= 0; i--) {
+              const m = s.matches[i];
+              tr.insertText(replacement, m.from, m.to);
+            }
+            dispatch(tr);
+          }
+          return true;
+        },
+    };
+  },
+});

src/export/epub.ts

@@ -284,9 +284,12 @@ function contentOpf(
 function navXhtml(book: Book): string {
   const items = book.chapters
     .map((chapter, i) => {
+      if (chapter.noTitle && chapterKind(chapter) !== "body") return "";
       const fallback = chapterKind(chapter) === "body" ? `Chapter ${bodyNumber(book.chapters, i)}` : "Untitled";
-      return `      <li><a href="chapter-${i + 1}.xhtml">${esc(chapter.title || fallback)}</a></li>`;
+      const label = chapter.noTitle ? fallback : chapter.title || fallback;
+      return `      <li><a href="chapter-${i + 1}.xhtml">${esc(label)}</a></li>`;
     })
+    .filter(Boolean)
     .join("\n");
   return `<?xml version="1.0" encoding="UTF-8"?>
 <html xmlns="http://www.w3.org/1999/xhtml" xmlns:epub="http://www.idpf.org/2007/ops" lang="${attr(book.metadata.language || "en")}">
@@ -311,6 +314,7 @@ function chapterXhtml(book: Book, index: number, paths: Map<string, string>): st
   const num = bodyNumber(book.chapters, index);
   const title = chapter.title || (kind === "body" ? `Chapter ${num}` : "Untitled");
   const eyebrow = kind === "body" ? `<p class="eyebrow">Chapter ${num}</p>` : "";
+  const heading = chapter.noTitle ? "" : `<h1>${esc(title)}</h1>`;
   return `<?xml version="1.0" encoding="UTF-8"?>
 <html xmlns="http://www.w3.org/1999/xhtml" xmlns:epub="http://www.idpf.org/2007/ops" lang="${attr(book.metadata.language || "en")}">
   <head>
@@ -320,7 +324,7 @@ function chapterXhtml(book: Book, index: number, paths: Map<string, string>): st
   <body epub:type="${kind === "body" ? "chapter" : kind === "front" ? "frontmatter" : "backmatter"}">
     <header class="chapter-opener">
       ${eyebrow}
-      <h1>${esc(title)}</h1>
+      ${heading}
     </header>
     ${chapterBody(chapter.content, paths)}
   </body>

src/export/typst.ts

@@ -139,9 +139,11 @@ function preamble(book: Book): string {
   align(center)[
     #if info.kind == "body" {
       text(font: "Hanken Grotesk", size: 8.5pt, weight: "semibold", tracking: 0.28em)[#upper("Chapter " + info.num)]
-      v(0.7em)
+      if not info.notitle { v(0.7em) }
+    }
+    #if not info.notitle {
+      heading(level: 1, numbering: none, outlined: info.toc)[#info.title]
     }
-    #heading(level: 1, numbering: none, outlined: info.toc)[#info.title]
   ]
   v(1.5em)
 }
@@ -262,6 +264,7 @@ function normTitle(title: string): string {
 
 function inToc(book: Book, index: number): boolean {
   const chapter = book.chapters[index];
+  if (chapter.noTitle && chapterKind(chapter) !== "body") return false;
   const title = cleanTitle(chapter.title) || "Untitled";
   return !(chapterKind(chapter) === "front" && normTitle(title) === normTitle(book.metadata.title));
 }
@@ -270,8 +273,9 @@ function openerCall(book: Book, index: number): string {
   const chapter = book.chapters[index];
   const kind = chapterKind(chapter);
   const num = kind === "body" ? String(bodyNumber(book.chapters, index)) : "";
-  const title = cleanTitle(chapter.title) || "Untitled";
-  return `#openchapter((kind: ${str(kind)}, num: ${str(num)}, title: ${str(title)}, toc: ${inToc(book, index)}))`;
+  const notitle = !!chapter.noTitle;
+  const title = notitle ? "" : cleanTitle(chapter.title) || "Untitled";
+  return `#openchapter((kind: ${str(kind)}, num: ${str(num)}, title: ${str(title)}, notitle: ${notitle}, toc: ${inToc(book, index)}))`;
 }
 
 export function bookToTypst(book: Book, paths: Map<string, string> = new Map(), coverPath?: string): string {

src/model/book.ts

@@ -70,6 +70,7 @@ export interface Chapter {
   content: JSONContent;
   updatedAt: number;
   kind?: ChapterKind;
+  noTitle?: boolean;
 }
 
 export interface PageType {
@@ -130,6 +131,11 @@ export function createPage(group: "front" | "back", title: string): Chapter {
   return { id: crypto.randomUUID(), title, content: emptyDoc(), kind: group, updatedAt: Date.now() };
 }
 
+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() };
+}
+
 export function createCover(): Cover {
   return { kind: "default", image: "", bg: COVER_PALETTES[0].bg, ink: COVER_PALETTES[0].ink };
 }

src/proofing.ts

@@ -0,0 +1,112 @@
+import { invoke } from "@tauri-apps/api/core";
+import type { Node as PMNode } from "@tiptap/pm/model";
+import { isDesktop } from "./ipc";
+import type { ProofIssue } from "./editor/proofing";
+
+export interface Issue {
+  start: number;
+  end: number;
+  kind: "spelling" | "grammar";
+  category: string;
+  message: string;
+  suggestions: string[];
+}
+
+export interface Segment {
+  from: number;
+  text: string;
+  cpStart: number;
+  cpLen: number;
+}
+
+function codepointLength(text: string): number {
+  let n = 0;
+  for (const _ of text) n++;
+  return n;
+}
+
+function utf16Offset(text: string, codepoints: number): number {
+  let units = 0;
+  let count = 0;
+  for (const ch of text) {
+    if (count >= codepoints) break;
+    units += ch.length;
+    count++;
+  }
+  return units;
+}
+
+export function docText(doc: PMNode): { text: string; segments: Segment[] } {
+  const segments: Segment[] = [];
+  let text = "";
+  let cp = 0;
+  let first = true;
+  doc.descendants((node, pos) => {
+    if (!node.isTextblock) return true;
+    if (!first) {
+      text += "\n\n";
+      cp += 2;
+    }
+    first = false;
+    node.forEach((child, offset) => {
+      if (!child.isText) return;
+      const t = child.text ?? "";
+      const len = codepointLength(t);
+      segments.push({ from: pos + 1 + offset, text: t, cpStart: cp, cpLen: len });
+      text += t;
+      cp += len;
+    });
+    return false;
+  });
+  return { text, segments };
+}
+
+export function mapOffset(segments: Segment[], cpOffset: number): number {
+  for (const seg of segments) {
+    if (cpOffset < seg.cpStart) return seg.from;
+    if (cpOffset <= seg.cpStart + seg.cpLen) {
+      return seg.from + utf16Offset(seg.text, cpOffset - seg.cpStart);
+    }
+  }
+  const last = segments[segments.length - 1];
+  return last ? last.from + last.text.length : 0;
+}
+
+export async function proofText(text: string, opts: { spelling: boolean; grammar: boolean }): Promise<Issue[]> {
+  if (!isDesktop) return [];
+  return invoke<Issue[]>("proof_text", { text, spelling: opts.spelling, grammar: opts.grammar });
+}
+
+export async function rememberWord(word: string): Promise<void> {
+  if (!isDesktop) return;
+  await invoke("remember_word", { word });
+}
+
+export function issueSignature(issue: { kind: string; word: string; message: string }): string {
+  return `${issue.kind}|${issue.word}|${issue.message}`;
+}
+
+export async function runProof(
+  doc: PMNode,
+  opts: { spelling: boolean; grammar: boolean },
+  ignored: Set<string>
+): Promise<ProofIssue[]> {
+  const { text, segments } = docText(doc);
+  if (!text.trim()) return [];
+  const issues = await proofText(text, opts);
+  const chars = [...text];
+  return issues
+    .map((iss) => {
+      const word = chars.slice(iss.start, iss.end).join("");
+      return {
+        from: mapOffset(segments, iss.start),
+        to: mapOffset(segments, iss.end),
+        kind: iss.kind,
+        category: iss.category,
+        message: iss.message,
+        suggestions: iss.suggestions,
+        word,
+      };
+    })
+    .filter((i) => i.to > i.from && !ignored.has(issueSignature(i)));
+}

src/search-book.ts

@@ -0,0 +1,61 @@
+import type { JSONContent } from "@tiptap/core";
+import { buildRegex, type SearchOptions } from "./editor/search";
+
+function collectRuns(node: JSONContent, out: string[]) {
+  const children = node.content;
+  if (!children) return;
+  let run = "";
+  for (const child of children) {
+    if (child.type === "text") {
+      run += child.text ?? "";
+    } else {
+      if (run) {
+        out.push(run);
+        run = "";
+      }
+      collectRuns(child, out);
+    }
+  }
+  if (run) out.push(run);
+}
+
+export function countMatches(content: JSONContent, regex: RegExp): number {
+  const runs: string[] = [];
+  collectRuns(content, runs);
+  let count = 0;
+  for (const run of runs) {
+    regex.lastIndex = 0;
+    let m: RegExpExecArray | null;
+    while ((m = regex.exec(run)) !== null) {
+      count++;
+      if (m.index === regex.lastIndex) regex.lastIndex++;
+    }
+  }
+  return count;
+}
+
+export function replaceInContent(
+  content: JSONContent,
+  regex: RegExp,
+  replacement: string
+): { content: JSONContent; count: number } {
+  let count = 0;
+  const walk = (node: JSONContent): JSONContent => {
+    if (node.type === "text" && node.text) {
+      regex.lastIndex = 0;
+      const text = node.text.replace(regex, () => {
+        count++;
+        return replacement;
+      });
+      return text === node.text ? node : { ...node, text };
+    }
+    if (node.content) return { ...node, content: node.content.map(walk) };
+    return node;
+  };
+  const next = walk(content);
+  return { content: next, count };
+}
+
+export function bookRegex(query: string, options: SearchOptions): RegExp | null {
+  return buildRegex(query, options);
+}

src/store/useBook.ts

@@ -7,6 +7,7 @@ import {
   type ChapterKind,
   type Cover,
   chapterKind,
+  cloneChapter,
   createChapter,
   createPage,
   normalizeBook,
@@ -27,8 +28,10 @@ interface BookState {
   setActiveChapter: (id: string) => void;
   setChapterContent: (id: string, content: JSONContent) => void;
   setChapterTitle: (id: string, title: string) => void;
+  setChapterNoTitle: (id: string, noTitle: boolean) => void;
   addChapter: () => void;
   addPage: (group: "front" | "back", title: string) => void;
+  duplicateChapter: (id: string) => void;
   deleteChapter: (id: string) => void;
   moveChapter: (from: number, to: number, toKind?: ChapterKind) => void;
   setMetadata: (patch: Partial<BookMetadata>) => void;
@@ -63,6 +66,12 @@ export const useBook = create<BookState>((set) => ({
         ? { dirty: true, book: { ...s.book, chapters: s.book.chapters.map((c) => (c.id === id ? { ...c, title, updatedAt: Date.now() } : c)) } }
         : {}
     ),
+  setChapterNoTitle: (id, noTitle) =>
+    set((s) =>
+      s.book
+        ? { dirty: true, book: { ...s.book, chapters: s.book.chapters.map((c) => (c.id === id ? { ...c, noTitle, title: noTitle ? "" : c.title, updatedAt: Date.now() } : c)) } }
+        : {}
+    ),
   addChapter: () =>
     set((s) => {
       if (!s.book) return {};
@@ -82,6 +91,16 @@ export const useBook = create<BookState>((set) => ({
       chapters.splice(insertAt, 0, page);
       return { activeChapterId: page.id, dirty: true, book: { ...s.book, chapters } };
     }),
+  duplicateChapter: (id) =>
+    set((s) => {
+      if (!s.book) return {};
+      const index = s.book.chapters.findIndex((c) => c.id === id);
+      if (index === -1) return {};
+      const copy = cloneChapter(s.book.chapters[index]);
+      const chapters = [...s.book.chapters];
+      chapters.splice(index + 1, 0, copy);
+      return { activeChapterId: copy.id, dirty: true, book: { ...s.book, chapters } };
+    }),
   deleteChapter: (id) =>
     set((s) => {
       if (!s.book) return {};

src/store/useProofing.ts

@@ -0,0 +1,26 @@
+import { create } from "zustand";
+
+interface ProofingState {
+  spelling: boolean;
+  grammar: boolean;
+  ignored: Set<string>;
+  toggleSpelling: () => void;
+  toggleGrammar: () => void;
+  ignore: (signature: string) => void;
+  resetIgnored: () => void;
+}
+
+export const useProofing = create<ProofingState>((set) => ({
+  spelling: true,
+  grammar: false,
+  ignored: new Set(),
+  toggleSpelling: () => set((s) => ({ spelling: !s.spelling })),
+  toggleGrammar: () => set((s) => ({ grammar: !s.grammar })),
+  ignore: (signature) =>
+    set((s) => {
+      const ignored = new Set(s.ignored);
+      ignored.add(signature);
+      return { ignored };
+    }),
+  resetIgnored: () => set({ ignored: new Set() }),
+}));

src/styles/app.css

@@ -80,6 +80,8 @@ button {
 
 .icon-btn[data-on="true"] {
   color: var(--accent);
+  background: var(--accent-wash);
+  box-shadow: inset 0 0 0 1px var(--line-strong);
 }
 
 .dirty-dot {
@@ -355,12 +357,18 @@ body.resizing {
   transition: background 120ms var(--ease), color 120ms var(--ease);
 }
 
+.row-menu-item:hover {
+  background: var(--accent-wash);
+  color: var(--ink);
+}
+
 .row-menu-item.danger {
   color: var(--danger);
 }
 
 .row-menu-item.danger:hover {
   background: var(--danger-wash);
+  color: var(--danger);
 }
 
 .add-chapter {
@@ -628,6 +636,30 @@ body.resizing {
   color: var(--ink-faint);
 }
 
+.chapter-title-input:disabled {
+  color: var(--ink-faint);
+  -webkit-text-fill-color: var(--ink-faint);
+}
+
+.no-title-check {
+  display: inline-flex;
+  align-items: center;
+  gap: 7px;
+  margin-top: 14px;
+  font-family: var(--font-ui);
+  font-size: var(--t-2);
+  color: var(--ink-faint);
+  cursor: pointer;
+  user-select: none;
+}
+
+.no-title-check input {
+  width: 14px;
+  height: 14px;
+  cursor: pointer;
+  accent-color: var(--ink-soft);
+}
+
 .editor-host,
 .ProseMirror {
   outline: none;
@@ -1621,3 +1653,342 @@ body.resizing {
   color: var(--accent);
   background: var(--accent-wash);
 }
+
+.find-bar {
+  position: fixed;
+  top: 54px;
+  right: 18px;
+  z-index: 30;
+  display: flex;
+  align-items: flex-start;
+  gap: 4px;
+  padding: 7px;
+  background: var(--glass);
+  -webkit-backdrop-filter: blur(10px);
+  backdrop-filter: blur(10px);
+  border: 1px solid var(--line);
+  border-radius: var(--r-md);
+  box-shadow: var(--shadow-pop);
+  animation: find-drop 140ms var(--ease);
+}
+
+@keyframes find-drop {
+  from {
+    opacity: 0;
+    transform: translateY(-6px);
+  }
+  to {
+    opacity: 1;
+    transform: translateY(0);
+  }
+}
+
+.find-expand {
+  flex: none;
+  width: 20px;
+  align-self: stretch;
+  display: grid;
+  place-items: center;
+  border-radius: var(--r-sm);
+  color: var(--ink-faint);
+  transition: background 120ms var(--ease), color 120ms var(--ease);
+}
+
+.find-expand:hover {
+  background: var(--accent-wash);
+  color: var(--ink);
+}
+
+.find-stack {
+  display: flex;
+  flex-direction: column;
+  gap: 6px;
+}
+
+.find-row {
+  display: flex;
+  align-items: center;
+  gap: 4px;
+}
+
+.find-input {
+  width: 196px;
+  height: 28px;
+  padding: 0 10px;
+  border: 1px solid var(--line-strong);
+  border-radius: var(--r-sm);
+  background: var(--raised);
+  color: var(--ink);
+  font-family: var(--font-ui);
+  font-size: var(--t-2);
+}
+
+.find-input::placeholder {
+  color: var(--ink-faint);
+}
+
+.find-input:focus {
+  outline: none;
+  border-color: var(--accent);
+}
+
+.find-count {
+  min-width: 66px;
+  padding: 0 4px;
+  font-size: var(--t-1);
+  color: var(--ink-faint);
+  white-space: nowrap;
+  text-align: right;
+}
+
+.find-btn {
+  width: 26px;
+  height: 26px;
+  flex: none;
+  display: grid;
+  place-items: center;
+  border-radius: var(--r-sm);
+  color: var(--ink-soft);
+  transition: background 120ms var(--ease), color 120ms var(--ease);
+}
+
+.find-btn:hover:not(:disabled) {
+  background: var(--accent-wash);
+  color: var(--ink);
+}
+
+.find-btn:disabled {
+  opacity: 0.4;
+  cursor: default;
+}
+
+.find-toggle {
+  height: 26px;
+  min-width: 28px;
+  padding: 0 6px;
+  display: grid;
+  place-items: center;
+  border-radius: var(--r-sm);
+  color: var(--ink-soft);
+  font-family: var(--font-ui);
+  font-size: var(--t-2);
+  font-weight: 600;
+  transition: background 120ms var(--ease), color 120ms var(--ease);
+}
+
+.find-toggle:hover {
+  background: var(--accent-wash);
+  color: var(--ink);
+}
+
+.find-toggle[data-on="true"] {
+  background: var(--accent);
+  color: var(--accent-contrast);
+}
+
+.find-ww {
+  text-decoration: underline;
+  text-underline-offset: 2px;
+}
+
+.find-action {
+  height: 28px;
+  padding: 0 12px;
+  border-radius: var(--r-sm);
+  background: var(--accent-wash);
+  color: var(--ink-soft);
+  font-family: var(--font-ui);
+  font-size: var(--t-2);
+  font-weight: 600;
+  white-space: nowrap;
+  transition: background 120ms var(--ease), color 120ms var(--ease);
+}
+
+.find-action:hover:not(:disabled) {
+  background: var(--accent);
+  color: var(--accent-contrast);
+}
+
+.find-action:disabled {
+  opacity: 0.4;
+  cursor: default;
+}
+
+.find-scope {
+  height: 28px;
+  padding: 0 10px;
+  border-radius: var(--r-sm);
+  border: 1px solid var(--line-strong);
+  color: var(--ink-soft);
+  font-family: var(--font-ui);
+  font-size: var(--t-1);
+  white-space: nowrap;
+  transition: background 120ms var(--ease), color 120ms var(--ease);
+}
+
+.find-scope:hover {
+  background: var(--accent-wash);
+  color: var(--ink);
+}
+
+.search-match {
+  background: var(--accent-wash);
+  border-radius: 2px;
+}
+
+.search-match-current {
+  background: var(--selection);
+  border-radius: 2px;
+  box-shadow: 0 0 0 1.5px var(--accent);
+}
+
+.proof-mark {
+  cursor: pointer;
+  border-radius: 2px;
+  text-decoration: underline;
+  text-decoration-thickness: 2px;
+  text-underline-offset: 3px;
+  -webkit-box-decoration-break: clone;
+  box-decoration-break: clone;
+  transition: filter 120ms var(--ease);
+}
+
+.proof-mark.sev-error {
+  background: rgba(180, 69, 58, 0.13);
+  text-decoration-color: #b4453a;
+}
+
+.proof-mark.sev-warn {
+  background: rgba(168, 119, 24, 0.16);
+  text-decoration-color: #9c6e16;
+}
+
+.proof-mark.sev-suggest {
+  background: rgba(47, 110, 79, 0.13);
+  text-decoration-color: #2f6e4f;
+}
+
+.proof-mark:hover {
+  filter: brightness(0.96);
+}
+
+[data-theme="dark"] .proof-mark.sev-error {
+  background: rgba(217, 122, 111, 0.2);
+  text-decoration-color: #d97a6f;
+}
+
+[data-theme="dark"] .proof-mark.sev-warn {
+  background: rgba(217, 164, 65, 0.2);
+  text-decoration-color: #d9a441;
+}
+
+[data-theme="dark"] .proof-mark.sev-suggest {
+  background: rgba(111, 174, 132, 0.2);
+  text-decoration-color: #6fae84;
+}
+
+[data-theme="dark"] .proof-mark:hover {
+  filter: brightness(1.18);
+}
+
+.proof-pop {
+  position: fixed;
+  z-index: 50;
+  padding: 8px;
+  background: var(--paper);
+  border: 1px solid var(--line);
+  border-radius: var(--r-md);
+  box-shadow: var(--shadow-pop);
+}
+
+.proof-pop-kind {
+  display: inline-block;
+  margin: 0 0 6px 2px;
+  padding: 2px 8px;
+  border-radius: 999px;
+  font-family: var(--font-ui);
+  font-size: var(--t-1);
+  font-weight: 600;
+  letter-spacing: 0.04em;
+  text-transform: uppercase;
+}
+
+.proof-pop-kind.sev-error {
+  background: rgba(180, 69, 58, 0.14);
+  color: var(--danger-ink);
+}
+
+.proof-pop-kind.sev-warn {
+  background: rgba(168, 119, 24, 0.16);
+  color: #8a6012;
+}
+
+.proof-pop-kind.sev-suggest {
+  background: rgba(47, 110, 79, 0.14);
+  color: #2c6048;
+}
+
+[data-theme="dark"] .proof-pop-kind.sev-error {
+  color: #e58e84;
+}
+
+[data-theme="dark"] .proof-pop-kind.sev-warn {
+  color: #e0bb6b;
+}
+
+[data-theme="dark"] .proof-pop-kind.sev-suggest {
+  color: #8fc6a3;
+}
+
+.proof-pop-msg {
+  padding: 2px 4px 8px;
+  font-family: var(--font-ui);
+  font-size: var(--t-2);
+  color: var(--ink-soft);
+  line-height: 1.4;
+}
+
+.proof-pop-suggestions {
+  display: flex;
+  flex-wrap: wrap;
+  gap: 4px;
+}
+
+.proof-suggestion {
+  padding: 5px 10px;
+  border-radius: var(--r-sm);
+  background: var(--accent-wash);
+  color: var(--ink);
+  font-family: var(--font-ui);
+  font-size: var(--t-2);
+  font-weight: 600;
+  transition: background 120ms var(--ease), color 120ms var(--ease);
+}
+
+.proof-suggestion:hover {
+  background: var(--accent);
+  color: var(--accent-contrast);
+}
+
+.proof-pop-actions {
+  display: flex;
+  gap: 4px;
+  margin-top: 8px;
+  padding-top: 8px;
+  border-top: 1px solid var(--line);
+}
+
+.proof-action {
+  flex: 1;
+  padding: 6px 8px;
+  border-radius: var(--r-sm);
+  font-family: var(--font-ui);
+  font-size: var(--t-1);
+  color: var(--ink-soft);
+  transition: background 120ms var(--ease), color 120ms var(--ease);
+}
+
+.proof-action:hover {
+  background: var(--accent-wash);
+  color: var(--ink);
+}

src/updater.ts

@@ -0,0 +1,31 @@
+import { check } from "@tauri-apps/plugin-updater";
+import { relaunch } from "@tauri-apps/plugin-process";
+import { ask, message } from "@tauri-apps/plugin-dialog";
+
+let running = false;
+
+export async function checkForUpdates(silent: boolean) {
+  if (running) return;
+  running = true;
+  try {
+    const update = await check();
+    if (!update) {
+      if (!silent) await message("margin is up to date.", { title: "Check for Updates" });
+      return;
+    }
+    const notes = update.body ? `\n\n${update.body}` : "";
+    const install = await ask(`margin ${update.version} is available.${notes}\n\nInstall now and restart?`, {
+      title: "Update Available",
+      kind: "info",
+    });
+    if (!install) return;
+    await update.downloadAndInstall();
+    await relaunch();
+  } catch (err) {
+    if (!silent) {
+      await message(`Could not check for updates.\n\n${err}`, { title: "Update Failed", kind: "error" });
+    }
+  } finally {
+    running = false;
+  }
+}