feat(epub): add custom reader navigation and TOC

- Implement custom previous/next page buttons for EPUB viewer.
- Display current page number out of total pages.
- Introduce an in-viewer, toggleable table of contents (TOC) for quick chapter navigation.
- Hide default `react-reader` navigation arrows and title bar to prevent redundancy.
- Adjust `react-reader` styles to optimize content area and ensure custom controls are visible.
- Update description for EPUB theme setting in document settings.
- Add `ChevronLeftIcon` and `ChevronRightIcon` to icon library.
- Update Playwright tests to reflect new navigation button labels.

src/components/DocumentSettings.tsx

@@ -414,10 +414,10 @@ export function DocumentSettings({ isOpen, setIsOpen, epub, html }: {
                             onChange={(e) => updateConfigKey('epubTheme', e.target.checked)}
                             className="form-checkbox h-4 w-4 text-accent rounded border-muted"
                           />
-                          <span className="text-sm font-medium text-foreground">Use theme (experimental)</span>
+                          <span className="text-sm font-medium text-foreground">Use theme</span>
                         </label>
                         <p className="text-sm text-muted pl-6">
-                          Apply the current app theme to the EPUB viewer
+                          Apply the current app theme to the EPUB viewer background and text colors
                         </p>
                       </div>
                     )}

src/components/EPUBViewer.tsx

@@ -1,6 +1,6 @@
 'use client';
 
-import { useEffect, useRef, useCallback } from 'react';
+import { useEffect, useRef, useCallback, useState } from 'react';
 import dynamic from 'next/dynamic';
 import { useEPUB } from '@/contexts/EPUBContext';
 import { useTTS } from '@/contexts/TTSContext';
@@ -8,6 +8,7 @@ import { useConfig } from '@/contexts/ConfigContext';
 import { DocumentSkeleton } from '@/components/DocumentSkeleton';
 import { useEPUBTheme, getThemeStyles } from '@/hooks/epub/useEPUBTheme';
 import { useEPUBResize } from '@/hooks/epub/useEPUBResize';
+import { DotsVerticalIcon, ChevronLeftIcon, ChevronRightIcon } from '@/components/icons/Icons';
 
 const ReactReader = dynamic(() => import('react-reader').then(mod => mod.ReactReader), {
   ssr: false,
@@ -19,9 +20,12 @@ interface EPUBViewerProps {
 }
 
 export function EPUBViewer({ className = '' }: EPUBViewerProps) {
+  const [isTocOpen, setIsTocOpen] = useState(false);
   const {
     currDocData,
     currDocName,
+    currDocPage,
+    currDocPages,
     locationRef,
     handleLocationChanged,
     bookRef,
@@ -116,7 +120,62 @@ export function EPUBViewer({ className = '' }: EPUBViewerProps) {
 
   return (
     <div className={`h-full flex flex-col relative z-0 ${className}`} ref={containerRef}>
-      <div className="flex-1">
+      <div className="flex items-center justify-between px-2 py-1 border-b border-offbase bg-base text-xs text-muted">
+        <div className="flex items-center gap-2">
+          <button
+            type="button"
+            onClick={() => setIsTocOpen(open => !open)}
+            className="inline-flex items-center py-1 px-1 rounded-md border border-offbase bg-base text-foreground text-xs hover:bg-offbase transition-all duration-200 ease-in-out transform hover:scale-[1.09] hover:text-accent"
+            aria-label={isTocOpen ? 'Hide chapters' : 'Show chapters'}
+          >
+            <DotsVerticalIcon className="w-4 h-4" />
+          </button>
+          <button
+            type="button"
+            onClick={() => renditionRef.current?.prev()}
+            className="inline-flex items-center py-1 px-2 rounded-md border border-offbase bg-base text-foreground text-xs hover:bg-offbase transition-all duration-200 ease-in-out transform hover:scale-[1.09] hover:text-accent"
+            aria-label="Previous section"
+          >
+            <ChevronLeftIcon className="w-4 h-4" />
+          </button>
+        </div>
+        {currDocPages !== undefined && typeof currDocPage === 'number' && (
+          <span className="px-2 tabular-nums">
+            {currDocPage} / {currDocPages}
+          </span>
+        )}
+        <button
+          type="button"
+          onClick={() => renditionRef.current?.next()}
+          className="inline-flex items-center py-1 px-2 rounded-md border border-offbase bg-base text-foreground text-xs hover:bg-offbase transition-all duration-200 ease-in-out transform hover:scale-[1.09] hover:text-accent"
+          aria-label="Next section"
+        >
+          <ChevronRightIcon className="w-4 h-4" />
+        </button>
+      </div>
+      {isTocOpen && tocRef.current && tocRef.current.length > 0 && (
+        <div className="border-b border-offbase bg-background text-xs overflow-y-auto max-h-64 p-2">
+          <div className="font-semibold text-muted pb-1">Skip to chapters</div>
+          <div className="flex flex-wrap gap-1">
+            {tocRef.current.map((item, index) => (
+              <button
+                key={`${item.href}-${index}`}
+                type="button"
+                onClick={() => {
+                  if (item.href) {
+                    handleLocationChanged(item.href);
+                  }
+                  setIsTocOpen(false);
+                }}
+                className="w-full px-2 py-1 rounded-md text-foreground text-center bg-base hover:bg-offbase hover:text-accent transition-colors duration-150"
+              >
+                {item.label}
+              </button>
+            ))}
+          </div>
+        </div>
+      )}
+      <div className="flex-1 min-h-0">
         <ReactReader
           loadingView={<DocumentSkeleton />}
           key={'epub-reader'}
@@ -125,8 +184,8 @@ export function EPUBViewer({ className = '' }: EPUBViewerProps) {
           url={currDocData}
           title={currDocName}
           tocChanged={(_toc) => (tocRef.current = _toc)}
-          showToc={true}
+          showToc={false}
-          readerStyles={epubTheme && getThemeStyles() || undefined}
+          readerStyles={getThemeStyles(epubTheme)}
           getRendition={(_rendition) => {
             setRendition(_rendition);
             updateTheme();

src/components/icons/Icons.tsx

@@ -373,6 +373,50 @@ export function DotsVerticalIcon(props: React.SVGProps<SVGSVGElement>) {
   );
 }
 
+export function ChevronLeftIcon(props: React.SVGProps<SVGSVGElement>) {
+  return (
+    <svg
+      xmlns="http://www.w3.org/2000/svg"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      className={props.className}
+      width={props.width || "1.25em"}
+      height={props.height || "1.25em"}
+      {...props}
+    >
+      <path
+        strokeLinecap="round"
+        strokeLinejoin="round"
+        strokeWidth="2"
+        d="M11 19l-7-7m0 0l7-7m-7 7h18"
+      />
+    </svg>
+  );
+}
+
+export function ChevronRightIcon(props: React.SVGProps<SVGSVGElement>) {
+  return (
+    <svg
+      xmlns="http://www.w3.org/2000/svg"
+      viewBox="0 0 24 24"
+      fill="none"
+      stroke="currentColor"
+      className={props.className}
+      width={props.width || "1.25em"}
+      height={props.height || "1.25em"}
+      {...props}
+    >
+      <path
+        strokeLinecap="round"
+        strokeLinejoin="round"
+        strokeWidth="2"
+        d="M13 5l7 7-7 7M5 5l7 7-7 7"
+      />
+    </svg>
+  );
+}
+
 export function SpeedometerIcon(props: React.SVGProps<SVGSVGElement>) {
   return (
     <svg

src/hooks/epub/useEPUBTheme.ts

@@ -2,14 +2,41 @@ import { useCallback, useEffect } from 'react';
 import { Rendition } from 'epubjs';
 import { ReactReaderStyle, IReactReaderStyle } from 'react-reader';
 
-export const getThemeStyles = (): IReactReaderStyle => {
+// Returns ReactReader styles, with:
-  const baseStyle = {
+// - default look when epubTheme === false (except hiding built-in arrows)
-    ...ReactReaderStyle,
+// - themed colors + layout tweaks when epubTheme === true
-    readerArea: {
+export const getThemeStyles = (epubTheme: boolean): IReactReaderStyle => {
-      ...ReactReaderStyle.readerArea,
+  const baseStyle = ReactReaderStyle;
-      transition: undefined,
+
-    }
+  // Always hide the built-in prev/next arrow buttons so we can
-  };
+  // provide our own navigation controls outside the reader.
+  if (!epubTheme) {
+    return {
+      ...baseStyle,
+      reader: {
+        ...baseStyle.reader,
+        // Always tighten the inset a bit for better use of space
+        top: 8,
+        left: 8,
+        right: 8,
+        bottom: 8,
+      },
+      prev: {
+        ...baseStyle.prev,
+        display: 'none',
+        pointerEvents: 'none',
+      },
+      next: {
+        ...baseStyle.next,
+        display: 'none',
+        pointerEvents: 'none',
+      },
+      titleArea: {
+        ...baseStyle.titleArea,
+        display: 'none',
+      },
+    };
+  }
 
   const colors = {
     background: getComputedStyle(document.documentElement).getPropertyValue('--background'),
@@ -21,6 +48,25 @@ export const getThemeStyles = (): IReactReaderStyle => {
 
   return {
     ...baseStyle,
+    reader: {
+      ...baseStyle.reader,
+      // Reduce the large default inset (50px 50px 20px)
+      // so the EPUB content can use more of the available area.
+      top: 8,
+      left: 8,
+      right: 8,
+      bottom: 8,
+    },
+    prev: {
+      ...baseStyle.prev,
+      display: 'none',
+      pointerEvents: 'none',
+    },
+    next: {
+      ...baseStyle.next,
+      display: 'none',
+      pointerEvents: 'none',
+    },
     arrow: {
       ...baseStyle.arrow,
       color: colors.foreground,
@@ -54,6 +100,9 @@ export const getThemeStyles = (): IReactReaderStyle => {
     tocButton: {
       ...baseStyle.tocButton,
       color: colors.muted,
+      // Ensure the TOC toggle sits above the swipe wrapper
+      // and text iframe, avoiding z-index conflicts.
+      zIndex: 300,
     },
     tocAreaButton: {
       ...baseStyle.tocAreaButton,

tests/upload.spec.ts

@@ -43,9 +43,9 @@ test.describe('Document Upload Tests', () => {
   test('displays an EPUB document', async ({ page }) => {
     await uploadAndDisplay(page, 'sample.epub');
     await expectViewerForFile(page, 'sample.epub');
-    // Keep navigation button assertions
+    // Navigation controls should be exposed via accessible labels
-    await expect(page.getByRole('button', { name: '‹' })).toBeVisible();
+    await expect(page.getByRole('button', { name: 'Previous section' })).toBeVisible();
-    await expect(page.getByRole('button', { name: '›' })).toBeVisible();
+    await expect(page.getByRole('button', { name: 'Next section' })).toBeVisible();
   });
 
   test('displays a DOCX document as PDF after conversion', async ({ page }) => {