fix(web): lecteur PDF — pages blanches après rendu et base minimale stable

Le canvas PDF restait vide après rendu (blank-detected): la détection d'encre
reposait sur un seuil de blanc trop sensible et un fond de canvas non maîtrisé.
Le rendu passe à un fond sentinel explicite avec classification
rendered-ok/blank-detected et un seuil de pixels visibles.

Le lecteur est par ailleurs ramené à une base minimale stable: layout plein
viewport (app-main-reader), suppression des modes de lecture et des préférences
par livre, helpers de pagination/viewport extraits dans readerLayout.ts. Shell,
lecteurs CBZ/EPUB et styles alignés sur cette base.

Refs #31

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

apps/web/src/App.tsx

@@ -41,7 +41,11 @@ function renderRoute(route: Route, session: Session, refreshSession: () => Promi
       <AdminPage />
     );
 
-  return <AppShell session={session}>{content}</AppShell>;
+  return (
+    <AppShell session={session} readerLayout={route.name === "reader"}>
+      {content}
+    </AppShell>
+  );
 }
 
 export function App() {

apps/web/src/layout/AppShell.tsx

@@ -11,7 +11,7 @@ const navItems = [
   { href: "/me", label: "Profil", icon: UserRound }
 ];
 
-export function AppShell({ children, session }: { children: ReactNode; session: Session }) {
+export function AppShell({ children, session, readerLayout = false }: { children: ReactNode; session: Session; readerLayout?: boolean }) {
   return (
     <div className="app-shell">
       <aside className="side-rail">
@@ -32,7 +32,7 @@ export function AppShell({ children, session }: { children: ReactNode; session:
         </nav>
         <div className="session-chip">{session.user ? session.user.email : "Mode vitrine"}</div>
       </aside>
-      <main>{children}</main>
+      <main className={readerLayout ? "app-main-reader" : undefined}>{children}</main>
     </div>
   );
 }

apps/web/src/pages/ReaderPage.tsx

@@ -6,7 +6,6 @@ import { EpubReader } from "../reader/EpubReader";
 import { pageLocator, parseCbrPageLocator, parseCbzPageLocator, parsePdfPageLocator, pdfPagePercent } from "../reader/locators";
 import { PdfReader } from "../reader/PdfReader";
 import { ReaderShell, type ReaderControls } from "../reader/ReaderShell";
-import { useReaderPreferences } from "../reader/useReaderPreferences";
 import { useReaderProgress } from "../reader/useReaderProgress";
 
 const idleControls: ReaderControls = {
@@ -23,9 +22,7 @@ export function ReaderPage({ bookId }: { bookId: number }) {
   const [error, setError] = useState<string>();
   const [page, setPage] = useState(1);
   const [readerControls, setReaderControls] = useState<ReaderControls>(idleControls);
-  const [controlsVisible, setControlsVisible] = useState(true);
+  const { progress, error: progressError, save, queueSave } = useReaderProgress(bookId);
-  const { progress, saving, error: progressError, save, queueSave } = useReaderProgress(bookId);
-  const { preferences, setMode, error: preferencesError } = useReaderPreferences(bookId);
 
   async function loadBook() {
     setLoading(true);
@@ -47,7 +44,6 @@ export function ReaderPage({ bookId }: { bookId: number }) {
 
   useEffect(() => {
     setReaderControls(idleControls);
-    setControlsVisible(true);
   }, [bookId]);
 
   useEffect(() => {
@@ -80,21 +76,15 @@ export function ReaderPage({ bookId }: { bookId: number }) {
     [book?.format, queueSave, save]
   );
 
-  const readerError = error ?? progressError ?? preferencesError;
+  const readerError = error ?? progressError;
 
   return (
     <ReaderShell
       title={book?.title ?? "Ouverture du lecteur"}
-      status={loading ? "Chargement" : saving ? "Sauvegarde" : "Progression synchronisee"}
       backHref={backHref}
-      progress={progress?.percent ?? 0}
       error={readerError}
       onRetry={error ? () => void loadBook() : undefined}
-      mode={preferences.mode}
-      onModeChange={setMode}
       controls={readerControls}
-      controlsVisible={controlsVisible}
-      onToggleControls={() => setControlsVisible((visible) => !visible)}
     >
       {!book ? (
         <div className="reader-fallback">
@@ -108,7 +98,6 @@ export function ReaderPage({ bookId }: { bookId: number }) {
           url={fileUrl}
           page={page}
           backHref={backHref}
-          mode={preferences.mode}
           onPageCommit={savePdfPage}
           onControlsChange={setReaderControls}
         />
@@ -116,7 +105,6 @@ export function ReaderPage({ bookId }: { bookId: number }) {
         <CbzReader
           bookId={book.id}
           page={page}
-          mode={preferences.mode}
           onPageCommit={saveComicPage}
           onControlsChange={setReaderControls}
         />
@@ -125,7 +113,7 @@ export function ReaderPage({ bookId }: { bookId: number }) {
           url={fileUrl}
           locator={progress?.locator}
           backHref={backHref}
-          mode={preferences.mode}
+          mode="horizontal"
           onLocatorChange={saveEpubLocator}
           onControlsChange={setReaderControls}
         />

apps/web/src/reader/CbzReader.tsx

@@ -1,39 +1,36 @@
 import { useCallback, useEffect, useRef, useState } from "react";
 import { api } from "../api/client";
-import type { CbzPagesDto, ReaderMode } from "../api/types";
+import type { CbzPagesDto } from "../api/types";
+import { clampReaderPage, orientedContainPageSize, readableViewportSize, readerPositionLabel, type ReaderSize } from "./readerLayout";
 import type { ReaderControls } from "./ReaderShell";
 
 type PageCommitStrategy = "immediate" | "queued";
 
-function scrollContainerFor(element: HTMLElement | null): HTMLElement | null {
-  return element?.closest(".reader-stage") as HTMLElement | null;
-}
-
 export function CbzReader({
   bookId,
   page,
-  mode,
   onPageCommit,
   onControlsChange
 }: {
   bookId: number;
   page: number;
-  mode: ReaderMode;
   onPageCommit: (page: number, pages: number, anchor?: number, strategy?: PageCommitStrategy) => void;
   onControlsChange: (controls: ReaderControls) => void;
 }) {
   const frameRef = useRef<HTMLDivElement>(null);
-  const restoredRef = useRef(false);
   const [pages, setPages] = useState<CbzPagesDto | null>(null);
-  const [error, setError] = useState<string>();
+  const [documentError, setDocumentError] = useState<string>();
-  const [imageError, setImageError] = useState(false);
+  const [pageError, setPageError] = useState<string>();
-  const [visiblePage, setVisiblePage] = useState(page);
+  const [documentAttempt, setDocumentAttempt] = useState(0);
+  const [retryAttempt, setRetryAttempt] = useState(0);
+  const [viewportSize, setViewportSize] = useState<ReaderSize | null>(null);
+  const [imageSize, setImageSize] = useState<ReaderSize | null>(null);
 
   useEffect(() => {
     let alive = true;
-    setError(undefined);
+    setDocumentError(undefined);
-    setImageError(false);
+    setPageError(undefined);
-    restoredRef.current = false;
+    setPages(null);
     api
       .cbzPages(bookId)
       .then((nextPages) => {
@@ -41,86 +38,95 @@ export function CbzReader({
         setPages(nextPages);
         if (page > nextPages.pageCount) onPageCommit(nextPages.pageCount, nextPages.pageCount, 1, "immediate");
       })
-      .catch(() => {
+      .catch((error) => {
-        if (alive) setError("Archive CBZ indisponible.");
+        if (!alive) return;
+        setDocumentError(error instanceof Error && error.message ? `Archive indisponible: ${error.message}` : "Archive indisponible.");
       });
     return () => {
       alive = false;
     };
-  }, [bookId]);
+  }, [bookId, documentAttempt]);
 
   const pageCount = pages?.pageCount ?? 1;
-  const currentPage = Math.max(1, Math.min(page, pageCount));
+  const currentPage = clampReaderPage(page, pageCount);
-  const displayedPage = mode === "vertical" ? Math.max(1, Math.min(visiblePage, pageCount)) : currentPage;
   const currentName = pages?.pages.find((item) => item.page === currentPage)?.name;
+  const fittedSize = viewportSize && imageSize ? orientedContainPageSize(viewportSize, imageSize) : null;
+  const imageStyle = fittedSize ? { width: `${fittedSize.width}px`, height: `${fittedSize.height}px` } : undefined;
 
   const go = useCallback(
     (nextPage: number) => {
-      const target = Math.max(1, Math.min(nextPage, pageCount));
+      if (!pages) return;
-      setImageError(false);
+      const target = clampReaderPage(nextPage, pages.pageCount);
-      if (mode === "vertical") {
+      setPageError(undefined);
-        frameRef.current?.querySelector(`[data-reader-page="${target}"]`)?.scrollIntoView({ block: "start" });
+      onPageCommit(target, pages.pageCount, 1, "immediate");
-        setVisiblePage(target);
-      }
-      onPageCommit(target, pageCount, mode === "vertical" ? 0 : 1, "immediate");
     },
-    [mode, onPageCommit, pageCount]
+    [onPageCommit, pages]
   );
 
-  const goTop = useCallback(() => go(1), [go]);
+  useEffect(() => {
+    setPageError(undefined);
+    setImageSize(null);
+  }, [bookId, currentPage, retryAttempt]);
+
+  useEffect(() => {
+    const frame = frameRef.current;
+    const stage = frame?.closest(".reader-stage") as HTMLElement | null;
+    const observedElement = stage ?? frame;
+    if (!observedElement) return;
+    const updateSize = () => {
+      const rect = observedElement.getBoundingClientRect();
+      const nextSize = readableViewportSize({ width: rect.width, height: rect.height });
+      if (nextSize) setViewportSize(nextSize);
+    };
+    updateSize();
+    const frameId = requestAnimationFrame(updateSize);
+    const observer = new ResizeObserver(updateSize);
+    observer.observe(observedElement);
+    return () => {
+      cancelAnimationFrame(frameId);
+      observer.disconnect();
+    };
+  }, []);
 
   useEffect(() => {
     onControlsChange({
-      canPrevious: !error && !imageError && displayedPage > 1,
+      canPrevious: Boolean(pages) && !documentError && !pageError && currentPage > 1,
-      canNext: !error && !imageError && displayedPage < pageCount,
+      canNext: Boolean(pages) && !documentError && !pageError && currentPage < pageCount,
-      canTop: !error && !imageError && displayedPage > 1,
+      positionLabel: pages ? readerPositionLabel(currentPage, pageCount) : "Chargement",
-      positionLabel: pages ? `${displayedPage} / ${pageCount}` : "Ouverture archive",
+      onPrevious: () => go(currentPage - 1),
-      onPrevious: () => go(displayedPage - 1),
+      onNext: () => go(currentPage + 1)
-      onNext: () => go(displayedPage + 1),
-      onTop: goTop
     });
-  }, [displayedPage, error, go, goTop, imageError, onControlsChange, pageCount, pages]);
+  }, [currentPage, documentError, go, onControlsChange, pageCount, pageError, pages]);
 
-  useEffect(() => {
+  if (documentError) {
-    if (mode !== "vertical") return;
-    const root = scrollContainerFor(frameRef.current);
-    if (!root || !pages) return;
-    const handleScroll = () => {
-      const rootRect = root.getBoundingClientRect();
-      const frames = Array.from(frameRef.current?.querySelectorAll<HTMLElement>("[data-reader-page]") ?? []);
-      const active = frames
-        .map((element) => {
-          const rect = element.getBoundingClientRect();
-          const overlap = Math.min(rootRect.bottom, rect.bottom) - Math.max(rootRect.top, rect.top);
-          const anchor = Math.max(0, Math.min(1, (rootRect.top - rect.top) / Math.max(1, rect.height)));
-          return { page: Number(element.dataset.readerPage), overlap, anchor };
-        })
-        .filter((item) => Number.isInteger(item.page) && item.overlap > 0)
-        .sort((left, right) => right.overlap - left.overlap)[0];
-      if (!active) return;
-      setVisiblePage(active.page);
-      onPageCommit(active.page, pageCount, active.anchor, "queued");
-    };
-    root.addEventListener("scroll", handleScroll, { passive: true });
-    handleScroll();
-    return () => root.removeEventListener("scroll", handleScroll);
-  }, [mode, onPageCommit, pageCount, pages]);
-
-  useEffect(() => {
-    if (mode !== "vertical" || !pages || restoredRef.current) return;
-    restoredRef.current = true;
-    requestAnimationFrame(() => {
-      frameRef.current?.querySelector(`[data-reader-page="${currentPage}"]`)?.scrollIntoView({ block: "start" });
-      setVisiblePage(currentPage);
-    });
-  }, [currentPage, mode, pages]);
-
-  if (error || imageError) {
     return (
-      <div className={`cbz-reader cbz-reader-${mode}`} ref={frameRef}>
+      <div className="cbz-reader" ref={frameRef}>
+        <div className="reader-fallback reader-fallback-error">
+          <span>{documentError}</span>
+          <button className="ghost-button" onClick={() => setDocumentAttempt((attempt) => attempt + 1)}>
+            Reessayer
+          </button>
+        </div>
+      </div>
+    );
+  }
+
+  if (!pages) {
+    return (
+      <div className="cbz-reader" ref={frameRef}>
         <div className="reader-fallback">
-          <span>{error ?? "Page CBZ indisponible."}</span>
+          <span>Chargement de l'archive</span>
-          <button className="ghost-button" onClick={() => go(currentPage)}>
+        </div>
+      </div>
+    );
+  }
+
+  if (pageError) {
+    return (
+      <div className="cbz-reader" ref={frameRef}>
+        <div className="reader-fallback reader-fallback-error">
+          <span>{pageError}</span>
+          <button className="ghost-button" onClick={() => setRetryAttempt((attempt) => attempt + 1)}>
             Reessayer
           </button>
         </div>
@@ -129,26 +135,25 @@ export function CbzReader({
   }
 
   return (
-    <div className={`cbz-reader cbz-reader-${mode}`} ref={frameRef}>
+    <div className="cbz-reader" ref={frameRef}>
-      {mode === "vertical" && pages ? (
+      <figure className="comic-page-frame" data-reader-page={currentPage}>
-        <div className="comic-strip">
+        {!imageSize && (
-          {pages.pages.map((item) => (
+          <div className="reader-fallback">
-            <figure className="comic-page-frame" data-reader-page={item.page} key={item.page}>
+            <span>Page {currentPage}</span>
-              <img
+          </div>
-                src={api.cbzPageUrl(bookId, item.page)}
+        )}
-                alt={item.name ?? `Page ${item.page}`}
+        <img
-                loading="lazy"
+          key={`${currentPage}-${retryAttempt}`}
-                decoding="async"
+          src={api.cbzPageUrl(bookId, currentPage)}
-                onError={() => setImageError(true)}
+          alt={currentName ?? `Page ${currentPage}`}
-              />
+          style={imageStyle}
-            </figure>
+          hidden={!imageSize}
-          ))}
+          onLoad={(event) => {
-        </div>
+            setImageSize({ width: event.currentTarget.naturalWidth, height: event.currentTarget.naturalHeight });
-      ) : (
+          }}
-        <figure className="comic-page-frame" data-reader-page={currentPage}>
+          onError={() => setPageError(`Page ${currentPage} indisponible.`)}
-          <img src={api.cbzPageUrl(bookId, currentPage)} alt={currentName ?? `Page ${currentPage}`} onError={() => setImageError(true)} />
+        />
-        </figure>
+      </figure>
-      )}
     </div>
   );
 }

apps/web/src/reader/PdfReader.tsx

@@ -1,10 +1,10 @@
 import { useCallback, useEffect, useRef, useState } from "react";
 import * as pdfjs from "pdfjs-dist";
 import { ReaderError } from "./ReaderError";
-import { pdfCanvasHasVisibleInk, pdfRenderScale } from "./pdfRender";
+import { classifyPdfCanvas, pdfCanvasVisible, pdfRenderScale, pdfSentinelBackground, type PdfRenderResult } from "./pdfRender";
 import { configurePdfWorker } from "./pdfWorker";
+import { clampReaderPage, readableViewportSize, readerPositionLabel, type ReaderSize } from "./readerLayout";
 import type { ReaderControls } from "./ReaderShell";
-import type { ReaderMode } from "../api/types";
 
 configurePdfWorker(pdfjs);
 
@@ -14,77 +14,196 @@ type PdfReaderProps = {
   url: string;
   page: number;
   backHref: string;
-  mode: ReaderMode;
   onPageCommit: (page: number, pages: number, anchor?: number, strategy?: PageCommitStrategy) => void;
   onControlsChange: (controls: ReaderControls) => void;
 };
 
-type PdfPageCanvasProps = {
+type PdfFailure = {
-  document: pdfjs.PDFDocumentProxy;
+  detail: string;
-  pageNumber: number;
+  technicalDetail: string;
-  mode: ReaderMode;
-  frameSize: { width: number; height: number };
-  onError: (message: string) => void;
 };
 
-let pdfLifecycle = Promise.resolve();
+type PdfPageStatus = "idle" | "loading" | PdfRenderResult | "render-failed";
 
-function enqueuePdfLifecycle<T>(work: () => Promise<T>) {
+function pdfTechnicalMessage(error: unknown) {
-  const run = pdfLifecycle.then(work, work);
+  if (error instanceof Error && error.message.trim()) return `${error.name}: ${error.message}`;
-  pdfLifecycle = run.then(() => undefined, () => undefined);
+  if (typeof error === "string" && error.trim()) return error;
-  return run;
+  return "Erreur inconnue.";
+}
+
+function pdfFailure(source: string, detail: string, context: Record<string, unknown>, error?: unknown): PdfFailure {
+  return {
+    detail,
+    technicalDetail: JSON.stringify(
+      {
+        source,
+        ...context,
+        error: error === undefined ? undefined : pdfTechnicalMessage(error)
+      },
+      null,
+      2
+    )
+  };
 }
 
 function isPdfTransitionError(error: unknown) {
   return error instanceof Error && (error.message.includes("worker is being destroyed") || error.message.includes("Rendering cancelled"));
 }
 
-function pdfReaderErrorMessage(error: unknown) {
-  if (isPdfTransitionError(error)) return "Le lecteur PDF termine une ouverture precedente.";
-  return "Le PDF n'a pas pu s'ouvrir.";
-}
-
 function scrollContainerFor(element: HTMLElement | null): HTMLElement | null {
   return element?.closest(".reader-stage") as HTMLElement | null;
 }
 
-function PdfPageCanvas({ document, pageNumber, mode, frameSize, onError }: PdfPageCanvasProps) {
+function afterNextPaint() {
+  return new Promise<void>((resolve) => requestAnimationFrame(() => resolve()));
+}
+
+export function PdfReader({ url, page, backHref, onPageCommit, onControlsChange }: PdfReaderProps) {
+  const frameRef = useRef<HTMLDivElement>(null);
   const canvasRef = useRef<HTMLCanvasElement>(null);
-  const wrapperRef = useRef<HTMLDivElement>(null);
+  const [documentProxy, setDocumentProxy] = useState<pdfjs.PDFDocumentProxy | null>(null);
-  const [visible, setVisible] = useState(mode === "horizontal");
+  const [pages, setPages] = useState(1);
-  const [rendered, setRendered] = useState(false);
+  const [documentError, setDocumentError] = useState<PdfFailure>();
+  const [pageError, setPageError] = useState<PdfFailure>();
+  const [loadingDocument, setLoadingDocument] = useState(true);
+  const [loadingPage, setLoadingPage] = useState(false);
+  const [pageRendered, setPageRendered] = useState(false);
+  const [pageStatus, setPageStatus] = useState<PdfPageStatus>("idle");
+  const [documentAttempt, setDocumentAttempt] = useState(0);
+  const [pageAttempt, setPageAttempt] = useState(0);
+  const [viewportSize, setViewportSize] = useState<ReaderSize | null>(null);
+
+  const currentPage = clampReaderPage(page, pages);
+  const showCanvas = pdfCanvasVisible(pageRendered, Boolean(pageError));
+
+  const go = useCallback(
+    (nextPage: number) => {
+      const target = clampReaderPage(nextPage, pages);
+      setPageError(undefined);
+      onPageCommit(target, pages, 1, "immediate");
+    },
+    [onPageCommit, pages]
+  );
 
   useEffect(() => {
-    if (mode === "horizontal") {
+    onControlsChange({
-      setVisible(true);
+      canPrevious: !loadingDocument && !documentError && !pageError && currentPage > 1,
-      return;
+      canNext: !loadingDocument && !documentError && !pageError && currentPage < pages,
+      positionLabel: loadingDocument ? "Chargement" : readerPositionLabel(currentPage, pages),
+      onPrevious: () => go(currentPage - 1),
+      onNext: () => go(currentPage + 1)
+    });
+  }, [currentPage, documentError, go, loadingDocument, onControlsChange, pageError, pages]);
+
+  useEffect(() => {
+    const frame = frameRef.current;
+    const stage = scrollContainerFor(frame);
+    const observedElement = stage ?? frame;
+    if (!observedElement) return;
+    const updateSize = () => {
+      const rect = observedElement.getBoundingClientRect();
+      const nextSize = readableViewportSize({ width: rect.width, height: rect.height });
+      if (nextSize) setViewportSize(nextSize);
+    };
+    updateSize();
+    const frameId = requestAnimationFrame(updateSize);
+    const observer = new ResizeObserver(updateSize);
+    observer.observe(observedElement);
+    return () => {
+      cancelAnimationFrame(frameId);
+      observer.disconnect();
+    };
+  }, []);
+
+  useEffect(() => {
+    let cancelled = false;
+    let loadingTask: pdfjs.PDFDocumentLoadingTask | undefined;
+    setLoadingDocument(true);
+    setDocumentError(undefined);
+    setPageError(undefined);
+    setPageRendered(false);
+    setPageStatus("idle");
+    setDocumentProxy(null);
+
+    async function loadDocument() {
+      try {
+        try {
+          new URL(url, window.location.href);
+        } catch (error) {
+          throw pdfFailure("uri", "PDF: URI de fichier invalide.", { url }, error);
+        }
+        configurePdfWorker(pdfjs);
+        loadingTask = pdfjs.getDocument({ url, withCredentials: true });
+        const loadedDocument = await loadingTask.promise;
+        if (cancelled) {
+          await loadingTask.destroy();
+          return;
+        }
+        setPages(loadedDocument.numPages);
+        setDocumentProxy(loadedDocument);
+        setLoadingDocument(false);
+      } catch (error) {
+        if (cancelled && isPdfTransitionError(error)) return;
+        if (!cancelled) {
+          setDocumentError(
+            typeof error === "object" && error && "detail" in error && "technicalDetail" in error
+              ? (error as PdfFailure)
+              : pdfFailure(
+                  "getDocument",
+                  "PDF: getDocument() a échoué.",
+                  {
+                    url,
+                    resolvedUrl: (() => {
+                      try {
+                        return new URL(url, window.location.href).toString();
+                      } catch {
+                        return null;
+                      }
+                    })(),
+                    workerSrc: pdfjs.GlobalWorkerOptions.workerSrc,
+                    hasWorkerPort: Boolean(pdfjs.GlobalWorkerOptions.workerPort)
+                  },
+                  error
+                )
+          );
+          setLoadingDocument(false);
+        }
+      }
     }
-    const wrapper = wrapperRef.current;
+
-    if (!wrapper) return;
+    void loadDocument();
-    const observer = new IntersectionObserver(
+    return () => {
-      (entries) => {
+      cancelled = true;
-        if (entries.some((entry) => entry.isIntersecting)) setVisible(true);
+      void loadingTask?.destroy();
-      },
+    };
-      { root: scrollContainerFor(wrapper), rootMargin: "900px 0px" }
+  }, [documentAttempt, url]);
-    );
-    observer.observe(wrapper);
-    return () => observer.disconnect();
-  }, [mode]);
 
   useEffect(() => {
-    if (!visible) return;
+    if (!documentProxy || !viewportSize) return;
+    const loadedDocument = documentProxy;
+    const readerViewport = viewportSize;
     let cancelled = false;
     let renderTask: pdfjs.RenderTask | undefined;
-    setRendered(false);
+    setLoadingPage(true);
+    setPageError(undefined);
+    setPageRendered(false);
+    setPageStatus("loading");
 
     async function renderPage() {
       try {
-        const pdfPage = await document.getPage(pageNumber);
+        let pdfPage: pdfjs.PDFPageProxy;
+        try {
+          pdfPage = await loadedDocument.getPage(currentPage);
+        } catch (error) {
+          throw pdfFailure("getPage", `PDF: getPage(${currentPage}) a échoué.`, { pageNumber: currentPage }, error);
+        }
         if (cancelled) return;
         const canvas = canvasRef.current;
-        if (!canvas) return;
+        if (!canvas) {
+          throw pdfFailure("react-canvas-ref", `PDF: canvas absent pour la page ${currentPage}.`, { pageNumber: currentPage });
+        }
         const baseViewport = pdfPage.getViewport({ scale: 1 });
-        const fitScale = pdfRenderScale(mode, frameSize, { width: baseViewport.width, height: baseViewport.height });
+        const fitScale = pdfRenderScale(readerViewport, { width: baseViewport.width, height: baseViewport.height });
         const pixelRatio = Math.min(2, window.devicePixelRatio || 1);
         const renderScale = Math.max(0.25, Math.min(3, fitScale)) * pixelRatio;
         const viewport = pdfPage.getViewport({ scale: renderScale });
@@ -95,189 +214,136 @@ function PdfPageCanvas({ document, pageNumber, mode, frameSize, onError }: PdfPa
         canvas.style.width = `${cssWidth}px`;
         canvas.style.height = `${cssHeight}px`;
         const context = canvas.getContext("2d", { alpha: false });
-        if (!context) return;
+        if (!context) {
-        context.fillStyle = "#f7f0df";
+          throw pdfFailure("canvas-context", `PDF: contexte canvas 2D indisponible pour la page ${currentPage}.`, {
-        context.fillRect(0, 0, canvas.width, canvas.height);
+            pageNumber: currentPage,
-        renderTask = pdfPage.render({ canvas, canvasContext: context, viewport });
+            canvasWidth: canvas.width,
-        await renderTask.promise;
+            canvasHeight: canvas.height
-        if (!pdfCanvasHasVisibleInk(context.getImageData(0, 0, canvas.width, canvas.height))) {
+          });
-          throw new Error(`La page PDF ${pageNumber} est blanche apres rendu.`);
+        }
+        if (canvas.width <= 0 || canvas.height <= 0 || cssWidth <= 0 || cssHeight <= 0) {
+          throw pdfFailure("canvas-size", `PDF: dimensions canvas invalides pour la page ${currentPage}.`, {
+            pageNumber: currentPage,
+            canvasWidth: canvas.width,
+            canvasHeight: canvas.height,
+            cssWidth,
+            cssHeight,
+            readerViewport
+          });
+        }
+        context.fillStyle = pdfSentinelBackground();
+        context.fillRect(0, 0, canvas.width, canvas.height);
+        try {
+          renderTask = pdfPage.render({ canvas, canvasContext: context, viewport });
+          await renderTask.promise;
+        } catch (error) {
+          throw pdfFailure(
+            "render-failed",
+            `PDF: render() a échoué pour la page ${currentPage}.`,
+            {
+              result: "render-failed",
+              pageNumber: currentPage,
+              baseViewport: { width: baseViewport.width, height: baseViewport.height },
+              renderViewport: { width: viewport.width, height: viewport.height },
+              canvasWidth: canvas.width,
+              canvasHeight: canvas.height,
+              cssWidth,
+              cssHeight,
+              readerViewport
+            },
+            error
+          );
+        }
+        await afterNextPaint();
+        if (cancelled) return;
+        const renderResult = classifyPdfCanvas(context.getImageData(0, 0, canvas.width, canvas.height));
+        if (renderResult === "blank-detected") {
+          setPageStatus("blank-detected");
+          setPageRendered(false);
+          setLoadingPage(false);
+          setPageError(
+            pdfFailure("blank-detected", `PDF: page ${currentPage} blanche détectée après rendu.`, {
+              result: "blank-detected",
+              pageNumber: currentPage,
+              baseViewport: { width: baseViewport.width, height: baseViewport.height },
+              renderViewport: { width: viewport.width, height: viewport.height },
+              canvasWidth: canvas.width,
+              canvasHeight: canvas.height,
+              cssWidth,
+              cssHeight,
+              readerViewport
+            })
+          );
+          return;
+        }
+        if (!cancelled) {
+          setPageStatus("rendered-ok");
+          setPageRendered(true);
+          setLoadingPage(false);
         }
-        if (!cancelled) setRendered(true);
       } catch (error) {
-        if (!cancelled && !isPdfTransitionError(error)) onError(pdfReaderErrorMessage(error));
+        if (cancelled || isPdfTransitionError(error)) return;
+        setPageRendered(false);
+        setPageStatus("render-failed");
+        setLoadingPage(false);
+        setPageError(
+          typeof error === "object" && error && "detail" in error && "technicalDetail" in error
+            ? (error as PdfFailure)
+            : pdfFailure("render-unclassified", `PDF: erreur non classée pendant le rendu de la page ${currentPage}.`, { pageNumber: currentPage }, error)
+        );
       }
     }
 
-    void enqueuePdfLifecycle(renderPage);
+    void renderPage();
     return () => {
       cancelled = true;
       renderTask?.cancel();
     };
-  }, [document, frameSize.height, frameSize.width, mode, onError, pageNumber, visible]);
+  }, [currentPage, documentProxy, pageAttempt, viewportSize]);
 
-  return (
+  if (documentError) {
-    <div className="pdf-page-frame" data-reader-page={pageNumber} ref={wrapperRef}>
+    return (
-      {!rendered && (
+      <div className="pdf-reader" ref={frameRef}>
-        <div className="reader-fallback">
-          <span>Page {pageNumber}</span>
-        </div>
-      )}
-      <canvas ref={canvasRef} />
-    </div>
-  );
-}
-
-export function PdfReader({ url, page, backHref, mode, onPageCommit, onControlsChange }: PdfReaderProps) {
-  const frameRef = useRef<HTMLDivElement>(null);
-  const restoredRef = useRef(false);
-  const [documentProxy, setDocumentProxy] = useState<pdfjs.PDFDocumentProxy | null>(null);
-  const [pages, setPages] = useState(1);
-  const [visiblePage, setVisiblePage] = useState(page);
-  const [error, setError] = useState<string>();
-  const [loading, setLoading] = useState(true);
-  const [attempt, setAttempt] = useState(0);
-  const [frameSize, setFrameSize] = useState({ width: 980, height: 900 });
-
-  const currentPage = Math.max(1, Math.min(page, pages));
-  const displayedPage = mode === "vertical" ? Math.max(1, Math.min(visiblePage, pages)) : currentPage;
-
-  const go = useCallback(
-    (nextPage: number) => {
-      const target = Math.max(1, Math.min(nextPage, pages));
-      if (mode === "vertical") {
-        frameRef.current?.querySelector(`[data-reader-page="${target}"]`)?.scrollIntoView({ block: "start" });
-        onPageCommit(target, pages, 0, "immediate");
-        setVisiblePage(target);
-      } else {
-        onPageCommit(target, pages, 1, "immediate");
-      }
-    },
-    [mode, onPageCommit, pages]
-  );
-
-  const goTop = useCallback(() => go(1), [go]);
-  const handlePageError = useCallback((message: string) => {
-    setError(message);
-  }, []);
-
-  useEffect(() => {
-    onControlsChange({
-      canPrevious: !loading && !error && displayedPage > 1,
-      canNext: !loading && !error && displayedPage < pages,
-      canTop: !loading && !error && displayedPage > 1,
-      positionLabel: loading ? "Ouverture PDF" : `${displayedPage} / ${pages}`,
-      onPrevious: () => go(displayedPage - 1),
-      onNext: () => go(displayedPage + 1),
-      onTop: goTop
-    });
-  }, [displayedPage, error, go, goTop, loading, onControlsChange, pages]);
-
-  useEffect(() => {
-    const frame = frameRef.current;
-    if (!frame) return;
-    const updateSize = () => {
-      const rect = frame.getBoundingClientRect();
-      setFrameSize({ width: Math.max(320, rect.width), height: Math.max(320, rect.height) });
-    };
-    updateSize();
-    const observer = new ResizeObserver(updateSize);
-    observer.observe(frame);
-    return () => observer.disconnect();
-  }, []);
-
-  useEffect(() => {
-    let cancelled = false;
-    let loadingTask: pdfjs.PDFDocumentLoadingTask | undefined;
-    setLoading(true);
-    setError(undefined);
-    setDocumentProxy(null);
-    restoredRef.current = false;
-
-    async function loadDocument() {
-      try {
-        configurePdfWorker(pdfjs);
-        loadingTask = pdfjs.getDocument({ url, withCredentials: true });
-        const loadedDocument = await loadingTask.promise;
-        if (cancelled) {
-          await loadingTask.destroy();
-          return;
-        }
-        setPages(loadedDocument.numPages);
-        setDocumentProxy(loadedDocument);
-        setLoading(false);
-      } catch (loadError) {
-        if (cancelled && isPdfTransitionError(loadError)) return;
-        if (!cancelled) {
-          setError(pdfReaderErrorMessage(loadError));
-          setLoading(false);
-        }
-      }
-    }
-
-    void enqueuePdfLifecycle(loadDocument);
-    return () => {
-      cancelled = true;
-      void loadingTask?.destroy();
-    };
-  }, [attempt, url]);
-
-  useEffect(() => {
-    if (mode !== "vertical") return;
-    const root = scrollContainerFor(frameRef.current);
-    if (!root || !documentProxy) return;
-    const handleScroll = () => {
-      const rootRect = root.getBoundingClientRect();
-      const frames = Array.from(frameRef.current?.querySelectorAll<HTMLElement>("[data-reader-page]") ?? []);
-      const active = frames
-        .map((element) => {
-          const rect = element.getBoundingClientRect();
-          const overlap = Math.min(rootRect.bottom, rect.bottom) - Math.max(rootRect.top, rect.top);
-          const anchor = Math.max(0, Math.min(1, (rootRect.top - rect.top) / Math.max(1, rect.height)));
-          return { page: Number(element.dataset.readerPage), overlap, anchor };
-        })
-        .filter((item) => Number.isInteger(item.page) && item.overlap > 0)
-        .sort((left, right) => right.overlap - left.overlap)[0];
-      if (!active) return;
-      setVisiblePage(active.page);
-      onPageCommit(active.page, pages, active.anchor, "queued");
-    };
-    root.addEventListener("scroll", handleScroll, { passive: true });
-    handleScroll();
-    return () => root.removeEventListener("scroll", handleScroll);
-  }, [documentProxy, mode, onPageCommit, pages]);
-
-  useEffect(() => {
-    if (mode !== "vertical" || !documentProxy || restoredRef.current) return;
-    restoredRef.current = true;
-    requestAnimationFrame(() => {
-      frameRef.current?.querySelector(`[data-reader-page="${currentPage}"]`)?.scrollIntoView({ block: "start" });
-      setVisiblePage(currentPage);
-    });
-  }, [currentPage, documentProxy, mode]);
-
-  return (
-    <div className={`pdf-reader pdf-reader-${mode}`} ref={frameRef}>
-      {error ? (
         <ReaderError
           title="Lecture PDF indisponible"
-          detail={error}
+          detail={documentError.detail}
+          technicalDetail={documentError.technicalDetail}
           downloadUrl={url}
           backHref={backHref}
-          onRetry={() => setAttempt((value) => value + 1)}
+          onRetry={() => setDocumentAttempt((value) => value + 1)}
         />
-      ) : loading || !documentProxy ? (
+      </div>
+    );
+  }
+
+  return (
+    <div className="pdf-reader" ref={frameRef}>
+      {loadingDocument || !documentProxy ? (
         <div className="reader-fallback">
           <span>Ouverture PDF</span>
         </div>
-      ) : mode === "vertical" ? (
+      ) : pageError ? (
-        <div className="pdf-strip">
+        <div className="pdf-page-frame" data-reader-page={currentPage}>
-          {Array.from({ length: pages }, (_, index) => (
+          <div className="reader-fallback reader-fallback-error">
-            <PdfPageCanvas key={index + 1} document={documentProxy} pageNumber={index + 1} mode={mode} frameSize={frameSize} onError={handlePageError} />
+            <span>{pageError.detail}</span>
-          ))}
+            <button className="ghost-button" onClick={() => setPageAttempt((value) => value + 1)}>
+              Reessayer
+            </button>
+            <details>
+              <summary>Détail technique</summary>
+              <pre>{pageError.technicalDetail}</pre>
+            </details>
+          </div>
         </div>
       ) : (
-        <PdfPageCanvas document={documentProxy} pageNumber={currentPage} mode={mode} frameSize={frameSize} onError={handlePageError} />
+        <div className="pdf-page-frame" data-reader-page={currentPage}>
+          {(!viewportSize || loadingPage || !pageRendered) && (
+            <div className="reader-fallback">
+              <span>Page {currentPage}</span>
+            </div>
+          )}
+          <canvas ref={canvasRef} data-pdf-render-status={pageStatus} style={{ visibility: showCanvas ? "visible" : "hidden" }} />
+        </div>
       )}
     </div>
   );

apps/web/src/reader/ReaderShell.tsx

@@ -1,180 +1,79 @@
-import { ArrowLeft, ArrowRight, ArrowUp, Columns2, Maximize2, Minimize2, RotateCcw, Rows3, Save } from "lucide-react";
+import { ArrowLeft, ArrowRight } from "lucide-react";
-import { useCallback, useEffect, useState, type ReactNode } from "react";
+import { useEffect, type ReactNode } from "react";
-import { ErrorRibbon, Meter } from "../components/ui";
+import { ErrorRibbon } from "../components/ui";
 import { navigate } from "../router";
-import type { ReaderMode } from "../api/types";
 
 export type ReaderControls = {
   canPrevious: boolean;
   canNext: boolean;
-  canTop?: boolean;
   positionLabel: string;
   onPrevious: () => void;
   onNext: () => void;
-  onTop?: () => void;
 };
 
 type ReaderShellProps = {
   title: string;
-  status: string;
   backHref: string;
-  progress: number;
   error?: string;
   onRetry?: () => void;
-  mode: ReaderMode;
-  onModeChange: (mode: ReaderMode) => void;
   controls: ReaderControls;
-  controlsVisible: boolean;
-  onToggleControls: () => void;
   children: ReactNode;
 };
 
-export function ReaderShell({
+function isFormField(target: EventTarget | null) {
-  title,
+  const element = target as HTMLElement | null;
-  status,
+  const tagName = element?.tagName.toLowerCase();
-  backHref,
+  return Boolean(element?.isContentEditable || tagName === "input" || tagName === "textarea" || tagName === "select");
-  progress,
+}
-  error,
-  onRetry,
-  mode,
-  onModeChange,
-  controls,
-  controlsVisible,
-  onToggleControls,
-  children
-}: ReaderShellProps) {
-  const [isFullscreen, setIsFullscreen] = useState(false);
-  const toggleFullscreen = useCallback(() => {
-    const root = document.querySelector(".reader-page");
-    if (!document.fullscreenElement) void root?.requestFullscreen();
-    else void document.exitFullscreen();
-  }, []);
 
+export function ReaderShell({ title, backHref, error, onRetry, controls, children }: ReaderShellProps) {
   useEffect(() => {
-    const updateFullscreen = () => setIsFullscreen(Boolean(document.fullscreenElement));
+    const handleKeyDown = (event: KeyboardEvent) => {
-    updateFullscreen();
+      if (isFormField(event.target)) return;
-    document.addEventListener("fullscreenchange", updateFullscreen);
+      if (event.key === "ArrowLeft" && controls.canPrevious) {
-    return () => document.removeEventListener("fullscreenchange", updateFullscreen);
+        event.preventDefault();
-  }, []);
+        controls.onPrevious();
+      }
+      if (event.key === "ArrowRight" && controls.canNext) {
+        event.preventDefault();
+        controls.onNext();
+      }
+    };
+    window.addEventListener("keydown", handleKeyDown);
+    return () => window.removeEventListener("keydown", handleKeyDown);
+  }, [controls]);
 
   return (
-    <div className={`reader-page reader-mode-${mode} ${controlsVisible ? "reader-controls-visible" : "reader-controls-hidden"}`}>
+    <div className="reader-page reader-mode-horizontal">
-      <header className="reader-topbar" onClick={(event) => event.stopPropagation()}>
+      <header className="reader-topbar">
         <button className="ghost-button" onClick={() => navigate(backHref)}>
           <ArrowLeft size={17} />
-          Fiche
+          Retour
         </button>
-        <div>
+        <strong className="reader-title">{title}</strong>
-          <strong>{title}</strong>
+        <span className="reader-position">{controls.positionLabel}</span>
-          <span>{status}</span>
+        <button className="ghost-button" onClick={controls.onPrevious} disabled={!controls.canPrevious}>
-        </div>
+          <ArrowLeft size={16} />
-        <div className="reader-toolbar">
+          Precedent
-          <button
+        </button>
-            className={`ghost-button reader-mode-button ${mode === "horizontal" ? "active" : ""}`}
+        <button className="ghost-button" onClick={controls.onNext} disabled={!controls.canNext}>
-            onClick={() => onModeChange("horizontal")}
+          Suivant
-            aria-label="Lecture horizontale"
+          <ArrowRight size={16} />
-            title="Lecture horizontale"
+        </button>
-          >
+      </header>
-            <Columns2 size={18} />
+      {error && (
-            Horizontal
+        <div className="reader-status">
-          </button>
+          <ErrorRibbon message={error} />
-          <button
+          {onRetry && (
-            className={`ghost-button reader-mode-button ${mode === "vertical" ? "active" : ""}`}
+            <button className="ghost-button" onClick={onRetry}>
-            onClick={() => onModeChange("vertical")}
+              Reessayer
-            aria-label="Lecture verticale"
-            title="Lecture verticale"
-          >
-            <Rows3 size={18} />
-            Vertical
-          </button>
-          <button className="ghost-button icon-only" onClick={toggleFullscreen} aria-label={isFullscreen ? "Quitter le plein ecran" : "Plein ecran"}>
-            {isFullscreen ? <Minimize2 size={18} /> : <Maximize2 size={18} />}
-          </button>
-          {error && onRetry ? (
-            <button className="ghost-button icon-only" onClick={onRetry} aria-label="Reessayer">
-              <RotateCcw size={18} />
             </button>
-          ) : (
-            <Save size={18} />
           )}
         </div>
-      </header>
+      )}
-      <div className="reader-status" onClick={(event) => event.stopPropagation()}>
+      <main className="reader-stage">
-        <ErrorRibbon message={error} />
-        <Meter value={progress} />
-      </div>
-      <div className="reader-stage" onClick={onToggleControls}>
-        {mode === "horizontal" && (
-          <>
-            <button
-              className="reader-side-button reader-side-left"
-              onClick={(event) => {
-                event.stopPropagation();
-                controls.onPrevious();
-              }}
-              disabled={!controls.canPrevious}
-              aria-label="Page precedente"
-            >
-              <ArrowLeft size={22} />
-            </button>
-            <button
-              className="reader-side-button reader-side-right"
-              onClick={(event) => {
-                event.stopPropagation();
-                controls.onNext();
-              }}
-              disabled={!controls.canNext}
-              aria-label="Page suivante"
-            >
-              <ArrowRight size={22} />
-            </button>
-            <button
-              className="reader-tap-zone reader-tap-left"
-              onClick={(event) => {
-                event.stopPropagation();
-                controls.onPrevious();
-              }}
-              disabled={!controls.canPrevious}
-              aria-label="Page precedente"
-            />
-            <button
-              className="reader-tap-zone reader-tap-right"
-              onClick={(event) => {
-                event.stopPropagation();
-                controls.onNext();
-              }}
-              disabled={!controls.canNext}
-              aria-label="Page suivante"
-            />
-          </>
-        )}
         <div className="reader-content">{children}</div>
-      </div>
+      </main>
-      <footer className="reader-stepper" onClick={(event) => event.stopPropagation()}>
-        {mode === "vertical" ? (
-          <button className="ghost-button" onClick={controls.onTop} disabled={!controls.canTop}>
-            <ArrowUp size={16} />
-            Haut
-          </button>
-        ) : (
-          <button className="ghost-button" onClick={controls.onPrevious} disabled={!controls.canPrevious}>
-            <ArrowLeft size={16} />
-            Precedent
-          </button>
-        )}
-        <span>{controls.positionLabel}</span>
-        {mode === "vertical" ? (
-          <button className="ghost-button" onClick={controls.onPrevious} disabled={!controls.canPrevious}>
-            <ArrowLeft size={16} />
-            Page precedente
-          </button>
-        ) : (
-          <button className="ghost-button" onClick={controls.onNext} disabled={!controls.canNext}>
-            Suivant
-            <ArrowRight size={16} />
-          </button>
-        )}
-      </footer>
     </div>
   );
 }

apps/web/src/reader/pdfRender.ts

@@ -1,34 +1,52 @@
-import type { ReaderMode } from "../api/types";
+import type { ReaderSize } from "./readerLayout";
 
-const PDF_RENDER_BACKGROUND = { red: 247, green: 240, blue: 223 };
+const PDF_SENTINEL_BACKGROUND = { red: 247, green: 240, blue: 223 };
-const PDF_BLANK_THRESHOLD = 245;
+const PDF_BACKGROUND_TOLERANCE = 5;
-const PDF_BACKGROUND_TOLERANCE = 4;
+const PDF_VISIBLE_DELTA = 10;
+const PDF_MIN_VISIBLE_PIXELS = 12;
 
-export function pdfRenderScale(mode: ReaderMode, frameSize: { width: number; height: number }, pageSize: { width: number; height: number }) {
+export type PdfRenderResult = "rendered-ok" | "blank-detected";
-  if (pageSize.width <= 0 || pageSize.height <= 0) return 1;
+
-  const fitWidth = frameSize.width / pageSize.width;
+export function pdfRenderScale(frameSize: ReaderSize, pageSize: ReaderSize) {
-  if (mode === "vertical") return Math.min(1.65, fitWidth);
+  if (frameSize.width <= 0 || frameSize.height <= 0 || pageSize.width <= 0 || pageSize.height <= 0) return 1;
-  return Math.min(fitWidth, frameSize.height / pageSize.height);
+  return Math.min(frameSize.width / pageSize.width, frameSize.height / pageSize.height);
 }
 
-function isNearRenderBackground(red: number, green: number, blue: number) {
+export function pdfCanvasVisible(pageRendered: boolean, hasPageError: boolean) {
+  return pageRendered && !hasPageError;
+}
+
+function isNearSentinel(red: number, green: number, blue: number) {
   return (
-    Math.abs(red - PDF_RENDER_BACKGROUND.red) <= PDF_BACKGROUND_TOLERANCE &&
+    Math.abs(red - PDF_SENTINEL_BACKGROUND.red) <= PDF_BACKGROUND_TOLERANCE &&
-    Math.abs(green - PDF_RENDER_BACKGROUND.green) <= PDF_BACKGROUND_TOLERANCE &&
+    Math.abs(green - PDF_SENTINEL_BACKGROUND.green) <= PDF_BACKGROUND_TOLERANCE &&
-    Math.abs(blue - PDF_RENDER_BACKGROUND.blue) <= PDF_BACKGROUND_TOLERANCE
+    Math.abs(blue - PDF_SENTINEL_BACKGROUND.blue) <= PDF_BACKGROUND_TOLERANCE
   );
 }
 
-export function pdfCanvasHasVisibleInk(imageData: Pick<ImageData, "data">) {
+function isVisibleInk(red: number, green: number, blue: number, alpha: number) {
+  if (alpha < 24) return false;
+  if (isNearSentinel(red, green, blue)) return false;
+  const distanceFromWhite = Math.max(255 - red, 255 - green, 255 - blue);
+  return distanceFromWhite >= PDF_VISIBLE_DELTA;
+}
+
+export function pdfCanvasHasVisibleContent(imageData: Pick<ImageData, "data">) {
+  let visiblePixels = 0;
   const data = imageData.data;
   for (let index = 0; index < data.length; index += 4) {
-    const red = data[index] ?? 255;
+    if (isVisibleInk(data[index] ?? 255, data[index + 1] ?? 255, data[index + 2] ?? 255, data[index + 3] ?? 255)) {
-    const green = data[index + 1] ?? 255;
+      visiblePixels += 1;
-    const blue = data[index + 2] ?? 255;
+      if (visiblePixels >= PDF_MIN_VISIBLE_PIXELS) return true;
-    const alpha = data[index + 3] ?? 255;
+    }
-    if (alpha === 0) continue;
-    const nearWhite = red >= PDF_BLANK_THRESHOLD && green >= PDF_BLANK_THRESHOLD && blue >= PDF_BLANK_THRESHOLD;
-    if (!nearWhite && !isNearRenderBackground(red, green, blue)) return true;
   }
   return false;
 }
+
+export function classifyPdfCanvas(imageData: Pick<ImageData, "data">): PdfRenderResult {
+  return pdfCanvasHasVisibleContent(imageData) ? "rendered-ok" : "blank-detected";
+}
+
+export function pdfSentinelBackground() {
+  return `rgb(${PDF_SENTINEL_BACKGROUND.red}, ${PDF_SENTINEL_BACKGROUND.green}, ${PDF_SENTINEL_BACKGROUND.blue})`;
+}

apps/web/src/reader/readerLayout.ts

@@ -0,0 +1,54 @@
+export type ReaderSize = {
+  width: number;
+  height: number;
+};
+
+export function clampReaderPage(page: number, pageCount: number) {
+  const safePageCount = Math.max(1, Math.floor(pageCount));
+  return Math.max(1, Math.min(Math.floor(page), safePageCount));
+}
+
+export function previousReaderPage(page: number, pageCount: number) {
+  return clampReaderPage(page - 1, pageCount);
+}
+
+export function nextReaderPage(page: number, pageCount: number) {
+  return clampReaderPage(page + 1, pageCount);
+}
+
+export function readerPositionLabel(page: number, pageCount: number) {
+  return `Page ${clampReaderPage(page, pageCount)} / ${Math.max(1, Math.floor(pageCount))}`;
+}
+
+export function containPageSize(viewport: ReaderSize, page: ReaderSize): ReaderSize {
+  if (viewport.width <= 0 || viewport.height <= 0 || page.width <= 0 || page.height <= 0) {
+    return { width: 0, height: 0 };
+  }
+  const scale = Math.min(viewport.width / page.width, viewport.height / page.height);
+  return {
+    width: Math.max(1, Math.floor(page.width * scale)),
+    height: Math.max(1, Math.floor(page.height * scale))
+  };
+}
+
+export function orientedContainPageSize(viewport: ReaderSize, page: ReaderSize): ReaderSize {
+  if (viewport.width <= 0 || viewport.height <= 0 || page.width <= 0 || page.height <= 0) {
+    return { width: 0, height: 0 };
+  }
+  const fitByHeight = page.height >= page.width;
+  const primaryScale = fitByHeight ? viewport.height / page.height : viewport.width / page.width;
+  const crossScale = fitByHeight ? viewport.width / page.width : viewport.height / page.height;
+  const scale = Math.min(primaryScale, crossScale);
+  return {
+    width: Math.max(1, Math.floor(page.width * scale)),
+    height: Math.max(1, Math.floor(page.height * scale))
+  };
+}
+
+export function readableViewportSize(size: ReaderSize): ReaderSize | null {
+  if (size.width < 32 || size.height < 32) return null;
+  return {
+    width: Math.floor(size.width),
+    height: Math.floor(size.height)
+  };
+}

apps/web/src/reader/readerRuntime.test.ts

@@ -1,6 +1,7 @@
 import { describe, expect, it } from "vitest";
 import { epubFileName } from "./EpubReader";
-import { pdfCanvasHasVisibleInk, pdfRenderScale } from "./pdfRender";
+import { clampReaderPage, containPageSize, nextReaderPage, orientedContainPageSize, previousReaderPage, readableViewportSize, readerPositionLabel } from "./readerLayout";
+import { classifyPdfCanvas, pdfCanvasHasVisibleContent, pdfCanvasVisible, pdfRenderScale } from "./pdfRender";
 import { configurePdfWorker, pdfWorkerSrc } from "./pdfWorker";
 import { readerErrorMessage } from "./ReaderError";
 
@@ -32,13 +33,80 @@ describe("reader runtime helpers", () => {
     expect(readerErrorMessage("", "EPUB indisponible")).toBe("EPUB indisponible");
   });
 
-  it("separates PDF fit-page and fit-width scales", () => {
+  it("fits PDF pages by containment inside the reader viewport", () => {
-    expect(pdfRenderScale("horizontal", { width: 800, height: 600 }, { width: 400, height: 800 })).toBe(0.75);
+    expect(pdfRenderScale({ width: 800, height: 600 }, { width: 400, height: 800 })).toBe(0.75);
-    expect(pdfRenderScale("vertical", { width: 800, height: 600 }, { width: 400, height: 800 })).toBe(1.65);
+    expect(pdfRenderScale({ width: 800, height: 600 }, { width: 800, height: 400 })).toBe(1);
   });
 
-  it("rejects blank PDF canvas renders", () => {
+  it("does not expose a PDF canvas before a successful page render", () => {
-    expect(pdfCanvasHasVisibleInk({ data: new Uint8ClampedArray([255, 255, 255, 255, 247, 240, 223, 255]) })).toBe(false);
+    expect(pdfCanvasVisible(false, false)).toBe(false);
-    expect(pdfCanvasHasVisibleInk({ data: new Uint8ClampedArray([255, 255, 255, 255, 32, 28, 24, 255]) })).toBe(true);
+    expect(pdfCanvasVisible(true, true)).toBe(false);
+    expect(pdfCanvasVisible(true, false)).toBe(true);
+  });
+
+  it("classifies blank PDF canvas data separately from render failures", () => {
+    expect(classifyPdfCanvas({ data: new Uint8ClampedArray([255, 255, 255, 255, 255, 255, 255, 255]) })).toBe("blank-detected");
+    expect(classifyPdfCanvas({ data: new Uint8ClampedArray([247, 240, 223, 255, 247, 240, 223, 255]) })).toBe("blank-detected");
+
+    const inkPixels = new Uint8ClampedArray(12 * 4);
+    for (let index = 0; index < inkPixels.length; index += 4) {
+      inkPixels[index] = 32;
+      inkPixels[index + 1] = 28;
+      inkPixels[index + 2] = 24;
+      inkPixels[index + 3] = 255;
+    }
+    expect(classifyPdfCanvas({ data: inkPixels })).toBe("rendered-ok");
+  });
+
+  it("does not treat isolated PDF canvas noise as visible content", () => {
+    const noisyPixels = new Uint8ClampedArray([
+      255, 255, 255, 255,
+      32, 28, 24, 255,
+      255, 255, 255, 255
+    ]);
+    expect(pdfCanvasHasVisibleContent({ data: noisyPixels })).toBe(false);
+  });
+
+  it("classifies very light but non-empty PDF canvas data as rendered", () => {
+    const lightInkPixels = new Uint8ClampedArray(12 * 4);
+    for (let index = 0; index < lightInkPixels.length; index += 4) {
+      lightInkPixels[index] = 244;
+      lightInkPixels[index + 1] = 244;
+      lightInkPixels[index + 2] = 244;
+      lightInkPixels[index + 3] = 255;
+    }
+
+    expect(classifyPdfCanvas({ data: lightInkPixels })).toBe("rendered-ok");
+  });
+
+  it("contains page media inside the reader viewport without cropping", () => {
+    expect(containPageSize({ width: 1200, height: 700 }, { width: 900, height: 1600 })).toEqual({ width: 393, height: 700 });
+    expect(containPageSize({ width: 1200, height: 700 }, { width: 1600, height: 900 })).toEqual({ width: 1200, height: 675 });
+  });
+
+  it("fits comic pages by intrinsic orientation without cropping", () => {
+    expect(orientedContainPageSize({ width: 1200, height: 700 }, { width: 900, height: 1600 })).toEqual({ width: 393, height: 700 });
+    expect(orientedContainPageSize({ width: 1200, height: 700 }, { width: 1600, height: 900 })).toEqual({ width: 1200, height: 675 });
+    expect(orientedContainPageSize({ width: 500, height: 900 }, { width: 1200, height: 900 })).toEqual({ width: 500, height: 375 });
+  });
+
+  it("ignores unusable reader viewport measurements", () => {
+    expect(readableViewportSize({ width: 0, height: 833 })).toBeNull();
+    expect(readableViewportSize({ width: 1, height: 1 })).toBeNull();
+    expect(readableViewportSize({ width: 1548.8, height: 833.2 })).toEqual({ width: 1548, height: 833 });
+  });
+
+  it("keeps the minimal reader on one clamped page", () => {
+    expect(clampReaderPage(0, 12)).toBe(1);
+    expect(clampReaderPage(8, 12)).toBe(8);
+    expect(clampReaderPage(99, 12)).toBe(12);
+    expect(readerPositionLabel(8, 12)).toBe("Page 8 / 12");
+  });
+
+  it("navigates page by page without leaving document bounds", () => {
+    expect(previousReaderPage(1, 12)).toBe(1);
+    expect(previousReaderPage(8, 12)).toBe(7);
+    expect(nextReaderPage(8, 12)).toBe(9);
+    expect(nextReaderPage(12, 12)).toBe(12);
   });
 });

apps/web/src/styles/app.css

@@ -68,6 +68,13 @@ main {
   padding: 28px;
 }
 
+main.app-main-reader {
+  height: 100vh;
+  min-height: 0;
+  padding: 0;
+  overflow: hidden;
+}
+
 .page-grid {
   display: grid;
   grid-template-columns: repeat(3, minmax(0, 1fr));
@@ -856,87 +863,82 @@ select {
 
 .reader-page {
   display: grid;
-  grid-template-rows: auto auto minmax(0, 1fr) auto;
+  grid-template-rows: auto auto minmax(0, 1fr);
-  gap: 10px;
+  gap: 8px;
   height: 100vh;
   min-height: 100vh;
-  padding: 14px;
+  padding: 10px;
   overflow: hidden;
   background: #120e0b;
 }
 
-.reader-page:fullscreen {
+main.app-main-reader .reader-page {
-  width: 100vw;
+  height: 100%;
-  height: 100vh;
+  min-height: 0;
 }
 
 .reader-topbar {
-  position: relative;
+  grid-row: 1;
-  z-index: 5;
+  display: flex;
-  justify-content: space-between;
+  align-items: center;
-  padding: 10px;
+  gap: 8px;
+  min-width: 0;
+  min-height: 42px;
+  padding: 6px 8px;
   border: 1px solid var(--line);
   border-radius: var(--radius);
   background: rgba(38, 26, 18, 0.84);
 }
 
-.reader-topbar div {
+.reader-title {
-  display: grid;
+  flex: 1 1 auto;
-  justify-items: center;
+  overflow: hidden;
-}
+  min-width: 0;
-
+  max-width: none;
-.reader-topbar span {
+  text-overflow: ellipsis;
-  color: var(--ink-muted);
-  font-size: 0.82rem;
-}
-
-.reader-toolbar {
-  display: flex;
-  align-items: center;
-  gap: 8px;
-}
-
-.reader-toolbar .icon-only {
-  width: 40px;
-  padding: 0;
-}
-
-.reader-toolbar .reader-mode-button {
-  gap: 7px;
-  padding-inline: 10px;
   white-space: nowrap;
 }
 
-.reader-toolbar .active {
+.reader-position {
-  border-color: rgba(213, 168, 77, 0.72);
+  flex: 0 0 auto;
-  color: var(--brass);
+  min-width: 92px;
-  background: rgba(213, 168, 77, 0.14);
+  color: var(--ink-muted);
+  text-align: center;
+}
+
+.reader-topbar .ghost-button {
+  flex: 0 0 auto;
+  min-height: 32px;
+  white-space: nowrap;
 }
 
 .reader-status {
-  position: relative;
+  grid-row: 2;
-  z-index: 4;
+  display: flex;
+  align-items: center;
+  gap: 8px;
+  min-width: 0;
 }
 
 .reader-stage {
+  grid-row: 3;
   position: relative;
   display: grid;
-  place-items: stretch;
+  place-items: center;
   min-height: 0;
   min-width: 0;
   padding: 0;
   overflow: hidden;
 }
 
-.reader-mode-vertical .reader-stage {
-  overflow-y: auto;
-  overscroll-behavior: contain;
-}
-
 .reader-content {
   display: grid;
+  place-items: center;
   min-height: 0;
   min-width: 0;
+  width: 100%;
+  height: 100%;
+  overflow: hidden;
 }
 
 .pdf-reader,
@@ -950,19 +952,19 @@ select {
   height: 100%;
 }
 
-.pdf-reader-vertical,
-.cbz-reader-vertical {
-  place-items: start center;
-  height: auto;
-}
-
 .epub-host {
   display: grid;
-  width: min(100%, 980px);
+  width: 100%;
   height: 100%;
   min-height: 0;
 }
 
+.epub-reader {
+  place-items: stretch;
+  overflow: auto;
+  padding: 14px;
+}
+
 .epub-view {
   width: 100%;
   height: 100%;
@@ -982,56 +984,23 @@ select {
   margin: 0;
 }
 
-.pdf-page-frame canvas {
+.pdf-page-frame canvas,
+.cbz-reader img {
   display: block;
-  max-width: min(100%, 980px);
+  width: auto;
+  height: auto;
+  max-width: 100%;
   max-height: 100%;
   box-sizing: border-box;
   border: 1px solid var(--line);
   border-radius: var(--radius);
   background: #f7f0df;
+  object-fit: contain;
 }
 
 .cbz-reader img {
-  display: block;
+  max-width: 100%;
-  box-sizing: border-box;
-  max-width: min(100%, 980px);
   max-height: 100%;
-  border: 1px solid var(--line);
-  border-radius: var(--radius);
-  background: #f7f0df;
-  object-fit: contain;
-}
-
-.reader-mode-vertical .pdf-reader,
-.reader-mode-vertical .cbz-reader {
-  align-content: start;
-  padding-bottom: 20px;
-}
-
-.pdf-strip,
-.comic-strip {
-  display: grid;
-  justify-items: center;
-  gap: 18px;
-  width: 100%;
-  padding: 0 0 24px;
-}
-
-.reader-mode-vertical .pdf-page-frame canvas,
-.reader-mode-vertical .cbz-reader img {
-  width: min(100%, 980px);
-  height: auto;
-  max-height: none;
-  object-fit: contain;
-}
-
-.reader-mode-horizontal .pdf-page-frame canvas,
-.reader-mode-horizontal .cbz-reader img {
-  width: auto;
-  height: auto;
-  max-height: 100%;
-  object-fit: contain;
 }
 
 .reader-fallback {
@@ -1044,71 +1013,6 @@ select {
   color: var(--ink-muted);
 }
 
-.reader-stepper {
-  position: relative;
-  z-index: 5;
-  display: flex;
-  align-items: center;
-  justify-content: center;
-  gap: 12px;
-  min-height: 46px;
-  padding: 6px;
-  border: 1px solid var(--line);
-  border-radius: var(--radius);
-  background: rgba(38, 26, 18, 0.84);
-}
-
-.reader-stepper span {
-  min-width: 92px;
-  color: var(--ink-muted);
-  text-align: center;
-}
-
-.reader-side-button,
-.reader-tap-zone {
-  position: absolute;
-  top: 0;
-  bottom: 0;
-  z-index: 3;
-  border: 0;
-  background: transparent;
-}
-
-.reader-side-button {
-  display: grid;
-  place-items: center;
-  width: 58px;
-  color: var(--ink);
-  opacity: 0.66;
-}
-
-.reader-side-button:hover {
-  opacity: 1;
-  background: rgba(255, 255, 255, 0.04);
-}
-
-.reader-side-button:disabled,
-.reader-tap-zone:disabled {
-  pointer-events: none;
-  opacity: 0;
-}
-
-.reader-side-left,
-.reader-tap-left {
-  left: 0;
-}
-
-.reader-side-right,
-.reader-tap-right {
-  right: 0;
-}
-
-.reader-tap-zone {
-  display: none;
-  width: 34%;
-  opacity: 0;
-}
-
 .reader-error {
   display: grid;
   gap: 14px;
@@ -1186,6 +1090,12 @@ select {
     padding: 16px 16px 86px;
   }
 
+  main.app-main-reader {
+    height: calc(100vh - 58px);
+    padding: 0 0 58px;
+    overflow: hidden;
+  }
+
   .page-grid {
     grid-template-columns: 1fr;
   }
@@ -1251,71 +1161,7 @@ select {
     gap: 8px;
   }
 
-  .reader-topbar div {
-    min-width: 0;
-  }
-
-  .reader-topbar strong {
-    overflow: hidden;
-    max-width: 38vw;
-    text-overflow: ellipsis;
-    white-space: nowrap;
-  }
-
-  .reader-toolbar {
-    gap: 5px;
-  }
-
-  .reader-side-button {
-    display: none;
-  }
-
-  .reader-tap-zone {
-    display: block;
-  }
-
-  .reader-controls-hidden .reader-topbar,
-  .reader-controls-hidden .reader-status,
-  .reader-controls-hidden .reader-stepper {
-    opacity: 0;
-    pointer-events: none;
-  }
-
-  .reader-controls-hidden {
-    grid-template-rows: 0 0 minmax(0, 1fr) 0;
-    gap: 0;
-  }
-
-  .reader-controls-hidden .reader-topbar,
-  .reader-controls-hidden .reader-status,
-  .reader-controls-hidden .reader-stepper {
-    overflow: hidden;
-    min-height: 0;
-    padding-top: 0;
-    padding-bottom: 0;
-  }
-
-  .reader-topbar,
-  .reader-status,
-  .reader-stepper {
-    transition: opacity 0.16s ease;
-  }
-
-  .reader-stepper {
-    gap: 8px;
-  }
-
-  .reader-stepper .ghost-button {
-    flex: 1 1 0;
-    min-width: 0;
-  }
-
   .epub-host {
     width: 100%;
   }
-
-  .reader-mode-vertical .pdf-reader canvas,
-  .reader-mode-vertical .cbz-reader img {
-    width: 100%;
-  }
 }