feat(reader): hash router, zero-flicker reload, honest weighted progress, and smart chapter detection

TODO.md

@@ -120,21 +120,21 @@
 
 ---
 
-### 6. 🔄 Комплексная переработка навигации, роутинга и честного прогресса чтения (In Progress)
+### 6. 🔄 Комплексная переработка навигации, роутинга и честного прогресса чтения (Completed)
-- [ ] **6.1. Нативная маршрутизация окон (URL Hash Router & Zero-Flicker F5)**:
+- [x] **6.1. Нативная маршрутизация окон (URL Hash Router & Zero-Flicker F5)**:
   - Внедрение хэш-роутинга: `#dictionary`, `#srs`, `#bookshelf`, `#reader/:book_id`, `#reader/:book_id/ch/:chapter_idx`.
   - Синхронное переключение `view` при старте скрипта (до любых сетевых запросов авторизации): если в URL `#reader/...`, сразу скрывать `#dictionary-view` и показывать скелетон читалки, устраняя мигание словарем.
   - Развязка асинхронных вызовов: `loadBookshelf()` больше не должен принудительно гасить `readerInterface`, если уже инициировано открытие книги через `openBook()`.
   - Поддержка нативной истории браузера (кнопки «Назад» / «Вперёд» на мыши, клавиатуре и мобильных свайпах).
   - Автоматическая синхронизация активного экрана в URL и `localStorage`.
-- [ ] **6.2. Честный непрерывный расчет прогресса книги и главы (Weighted Reading Progress)**:
+- [x] **6.2. Честный непрерывный расчет прогресса книги и главы (Weighted Reading Progress)**:
   - Устранение бага ложных «100%»: полная ликвидация формулы `(current_ch + 1) / total_ch`, выдававшей 100% на первой странице одноглавных документов.
   - Прогресс текущей главы в реальном времени: непрерывный расчет от вертикального скролла (`scrollTop / (scrollHeight - clientHeight) * 100`) от 0% до 100%.
   - Взвешенный общий прогресс книги: расчет по объему слов прочитанных глав + точная доля текущей главы:
     $$\text{TotalProgress} = \frac{\sum_{i=0}^{\text{cur}-1} \text{words}(ch_i) + \text{words}(ch_{\text{cur}}) \times \frac{\text{ChapterPct}}{100}}{\text{TotalWords}} \times 100\%$$
   - Для документа на 1000 слов прогресс будет плавно расти: 0% $\rightarrow$ 15% $\rightarrow$ 50% $\rightarrow$ 100%.
   - Отображение честного суммарного прогресса на карточках книг в библиотеке и в тулбаре читалки.
-- [ ] **6.3. Интеллектуальный парсинг глав и оглавление (Smart Chapter & ToC Detection)**:
+- [x] **6.3. Интеллектуальный парсинг глав и оглавление (Smart Chapter & ToC Detection)**:
   - Расширение детектора глав в `app/reader.py`:
     - Markdown-заголовки всех уровней (`# `, `## `, `### `, `#### `).
     - Нумерованные разделы и модули (`1. `, `1.1 `, `2.0 `, `Section 1`, `Part 1`, `Раздел 1`).
@@ -142,7 +142,7 @@
     - Жирные заголовки в начале абзацев (`**Chapter 1**`, `**Глава 1**`).
   - Адаптивный порог авто-разбивки: снижение порога чанкования текста без явных глав с 3000 до 800–1000 слов, чтобы даже небольшие статьи имели логическое деление на части.
   - Интерактивное оглавление со статусами прочтения: `✔ Прочитано`, `▶ В процессе (45%)`, `○ Не начато`.
-- [ ] **6.4. Устойчивая фиксация позиции чтения (Paragraph Anchor + Scroll)**:
+- [x] **6.4. Устойчивая фиксация позиции чтения (Paragraph Anchor + Scroll)**:
   - Сохранение не только пикселей `scrollTop`, но и индекса первого видимого абзаца (`anchor_paragraph_idx`).
   - Устойчивость к изменению шрифта `Aa` и ориентации экрана: восстановление скролла к конкретному предложению/абзацу, а не слепым пикселям.
   - Фиксация скролл-контейнера `#reader-scroll-area` с аппаратным ускорением на мобильных.

app/reader.py

@@ -319,38 +319,180 @@ def parse_text(content: str, title: str = "Untitled", author: str = "") -> Tuple
             if len(lines) > 1:
                 content = "\n".join(lines[1:]).strip()
 
-    heading_pattern = re.compile(
+def detect_text_headings(content: str) -> List[Dict]:
-        r"^[ \t]*(?:"
+    """
-        r"#{1,3}[ \t]+(.+)|"
+    Detects section and chapter headings with high accuracy across Markdown,
-        r"((?:Chapter|CHAPTER|Глава|ГЛАВА|Part|PART|Section|SECTION|Act|ACT|Scene|SCENE)[ \t]+[0-9IVXLCDMivxlcdm\w\.\-]+(?:[ \t]*[:\-–—\.][ \t]*.*|[ \t]+[^\n\r]+)?)"
+    numbered sections, explicit keywords, bold titles, and Setext styles.
-        r")[ \t]*$",
+    """
-        re.MULTILINE,
+    lines = content.split("\n")
+    line_starts = []
+    curr = 0
+    for l in lines:
+        line_starts.append(curr)
+        curr += len(l) + 1
+
+    kw_regex = re.compile(
+        r"^[ \t]*(?:\*\*)?(?:Chapter|CHAPTER|Глава|ГЛАВА|Part|PART|Часть|ЧАСТЬ|Section|SECTION|Раздел|РАЗДЕЛ|Module|MODULE|Модуль|МОДУЛЬ|Unit|UNIT|Lesson|LESSON|Урок|УРОК|Topic|TOPIC|Тема|ТЕМА|Appendix|APPENDIX|Приложение|ПРИЛОЖЕНИЕ|Act|ACT|Scene|SCENE)[ \t]+(?:[0-9IVXLCDMivxlcdm\w\.\-]+)(?:[ \t]*[:\-–—\.][ \t]*[^\n\r*]+|[ \t]+[^\n\r*]+)?(?:\*\*)?[ \t]*$"
     )
 
-    matches = list(heading_pattern.finditer(content))
+    headings = []
+
+    for i, line in enumerate(lines):
+        trimmed = line.strip()
+        if not trimmed:
+            continue
+
+        prev_empty = (i == 0) or (not lines[i - 1].strip())
+        next_empty = (i == len(lines) - 1) or (not lines[i + 1].strip())
+
+        # 1. Markdown # heading (# to #####)
+        m_md = re.match(r"^#{1,5}[ \t]+(.+)$", trimmed)
+        if m_md:
+            clean_title = m_md.group(1).strip("#").strip()
+            headings.append({
+                "line_idx": i,
+                "start": line_starts[i],
+                "title": clean_title,
+                "type": "markdown",
+            })
+            continue
+
+        # 2. Setext heading: Title followed by === or ---
+        if i + 1 < len(lines):
+            next_line = lines[i + 1].strip()
+            if prev_empty and len(trimmed) <= 80 and not trimmed.startswith(("-", "*", "#", "`")):
+                if re.match(r"^={3,}$", next_line) or re.match(r"^-{3,}$", next_line):
+                    headings.append({
+                        "line_idx": i,
+                        "start": line_starts[i],
+                        "title": trimmed,
+                        "type": "setext",
+                    })
+                    continue
+
+        # 3. Explicit keywords (Chapter 1, Глава 2, Module 3, etc.)
+        if kw_regex.match(trimmed):
+            clean_title = trimmed.strip("*").strip()
+            headings.append({
+                "line_idx": i,
+                "start": line_starts[i],
+                "title": clean_title,
+                "type": "keyword",
+            })
+            continue
+
+        # 4. Bold heading on standalone line: **Title**
+        bold_m = re.match(r"^\*\*([A-ZА-ЯЁ0-9][^\n\r*]{2,70})\*\*$", trimmed)
+        if bold_m and prev_empty:
+            headings.append({
+                "line_idx": i,
+                "start": line_starts[i],
+                "title": bold_m.group(1).strip(),
+                "type": "bold",
+            })
+            continue
+
+        # 5. Numbered sections: e.g. 1. Title, 1.1 Title, 1. Title.
+        num_m = re.match(r"^([0-9]{1,2}(?:\.[0-9]{1,2})*\.?|[0-9]{1,2}\))[ \t]+([A-ZА-ЯЁ][^\n\r]{2,70})$", trimmed)
+        if num_m and prev_empty:
+            is_list = False
+            if i + 1 < len(lines):
+                next_t = lines[i + 1].strip()
+                if re.match(r"^[0-9]{1,2}(?:\.[0-9]{1,2})*\.?[ \t]+", next_t):
+                    is_list = True
+            if not is_list and not trimmed.endswith((",", ";")):
+                headings.append({
+                    "line_idx": i,
+                    "start": line_starts[i],
+                    "title": trimmed,
+                    "type": "numbered",
+                })
+                continue
+
+        # 6. Standalone ALL CAPS line (e.g. INTRODUCTION TO NETWORKS)
+        next_is_allcaps = (i + 1 < len(lines)) and bool(lines[i + 1].strip()) and lines[i + 1].strip().isupper()
+        if prev_empty and not next_is_allcaps and 4 <= len(trimmed) <= 60 and not trimmed.endswith((",", ";")):
+            if re.match(r"^[A-ZА-ЯЁ0-9\s:\-–—\.]+$", trimmed):
+                letters = re.findall(r"[A-ZА-ЯЁ]", trimmed)
+                words = trimmed.split()
+                if len(letters) >= 4 and (len(words) >= 2 or len(trimmed) >= 6):
+                    headings.append({
+                        "line_idx": i,
+                        "start": line_starts[i],
+                        "title": trimmed,
+                        "type": "allcaps",
+                    })
+                    continue
+
+    return headings
+
+
+def parse_text(content: str, title: str = "Untitled", author: str = "") -> Tuple[str, str, List[Dict[str, str]]]:
+    """
+    Parses plain text or Markdown into readable chapters.
+    Splits by intelligent heading detection (Markdown, numbered sections, keywords)
+    or chunks of ~1000 words.
+    """
+    content = content.replace("\r\n", "\n").replace("\r", "\n").strip()
+    if not content:
+        return title, author, [{"title": title if title != "Untitled" else "Chapter 1", "content": ""}]
+
+    lines = content.split("\n")
+    first_line = lines[0].strip()
+
+    # Extract title from first line or # Heading / <h1...> if default or generic README
+    if title == "Untitled" or title.lower().startswith("readme"):
+        if first_line.startswith("# "):
+            title = first_line.lstrip("# ").strip()
+            if len(lines) > 1:
+                content = "\n".join(lines[1:]).strip()
+        elif first_line.lower().startswith("title:"):
+            title = first_line.split(":", 1)[1].strip()
+            if len(lines) > 1:
+                content = "\n".join(lines[1:]).strip()
+        else:
+            h1_match = re.search(r"<h1[^>]*>(.*?)</h1>", content[:1500], re.IGNORECASE)
+            if h1_match:
+                detected = re.sub(r"<[^>]+>", "", h1_match.group(1)).strip()
+                if detected:
+                    title = detected
+
+    # Extract author from next line if missing
+    if not author:
+        lines = content.split("\n")
+        if lines and lines[0].lower().startswith(("author:", "by:")):
+            author = lines[0].split(":", 1)[1].strip()
+            if len(lines) > 1:
+                content = "\n".join(lines[1:]).strip()
+
+    detected_headings = detect_text_headings(content)
     chapters: List[Dict[str, str]] = []
 
-    if len(matches) >= 1:
+    if detected_headings:
         # Pre-chapter intro text
-        intro = content[: matches[0].start()].strip()
+        intro = content[: detected_headings[0]["start"]].strip()
         if intro and count_words(intro) > 10:
-            chapters.append({"title": "Introduction", "content": intro})
+            is_ru = any(ord(c) > 127 for c in intro[:200])
+            chapters.append({"title": "Введение" if is_ru else "Introduction", "content": intro})
 
-        for i, m in enumerate(matches):
+        for i, h in enumerate(detected_headings):
-            h_text = (m.group(1) or m.group(2)).strip()
+            start = h["start"]
-            start = m.start()
+            end = detected_headings[i + 1]["start"] if i + 1 < len(detected_headings) else len(content)
-            end = matches[i + 1].start() if i + 1 < len(matches) else len(content)
             body = content[start:end].strip()
             if body:
-                chapters.append({"title": h_text, "content": body})
+                chapters.append({"title": h["title"], "content": body})
 
     if not chapters:
-        # No headings detected: split by ~3000 words chunks
+        # No headings detected: split by ~1000 words chunks if long enough
-        chunks = split_long_text(content, target_words=3000)
+        total_w = count_words(content)
-        if len(chunks) == 1:
+        if total_w > 1200:
-            chapters = [{"title": title if title != "Untitled" else "Chapter 1", "content": chunks[0]}]
+            chunks = split_long_text(content, target_words=1000)
-        else:
+            is_ru = any(ord(c) > 127 for c in content[:200])
+            prefix = "Часть" if is_ru else "Chapter"
             for idx, chunk in enumerate(chunks, start=1):
-                chapters.append({"title": f"Chapter {idx}", "content": chunk})
+                chapters.append({"title": f"{prefix} {idx}", "content": chunk})
+        else:
+            chapters = [{"title": title if title != "Untitled" else "Chapter 1", "content": content}]
 
     return title, author, chapters
+

app/static/index.html

@@ -5,7 +5,7 @@
     <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no, viewport-fit=cover">
     <title>Notes — Персональный тренажер и словарь английского языка</title>
     <meta name="description" content="Защищённый персональный тренажёр и словарь английского языка с интервальными повторениями SRS SM-2, контекстным поиском и озвучкой">
-    <link rel="stylesheet" href="/static/css/style.css?v=3.4">
+    <link rel="stylesheet" href="/static/css/style.css?v=3.5">
     
     <!-- PWA meta and icons -->
     <link rel="manifest" href="/manifest.json">
@@ -1056,7 +1056,7 @@
     <!-- Audio Element for native streaming -->
     <audio id="global-audio-player" preload="none"></audio>
 
-    <script src="/static/js/app.js?v=3.4"></script>
+    <script src="/static/js/app.js?v=3.5"></script>
 </body>
 </html>
 

app/static/js/app.js

@@ -385,6 +385,42 @@ document.addEventListener('DOMContentLoaded', () => {
         return;
     }
 
+    // -----------------------------------------------------------------------
+    // Immediate Pre-flight Routing (Zero-flicker view restoration on F5)
+    // -----------------------------------------------------------------------
+    function applyInitialViewPreflight() {
+        let hash = window.location.hash || '';
+        if (!hash || hash === '#') {
+            try {
+                const lastView = localStorage.getItem('notes_active_view');
+                const lastBookId = localStorage.getItem('notes_active_book_id');
+                if (lastView === 'reader-view') {
+                    hash = lastBookId ? `#reader/book/${lastBookId}` : '#reader';
+                } else if (lastView === 'srs-view') {
+                    hash = '#srs';
+                }
+            } catch (e) {}
+        }
+
+        if (hash.startsWith('#reader') || hash === '#bookshelf') {
+            if (dictionaryView) dictionaryView.classList.add('hidden');
+            if (srsView) srsView.classList.add('hidden');
+            if (readerView) readerView.classList.remove('hidden');
+            updateMobileActiveTab('reader');
+            if (hash.includes('/book/')) {
+                if (bookshelfContainer) bookshelfContainer.classList.add('hidden');
+                if (readerInterface) readerInterface.classList.remove('hidden');
+                if (readerBookTitle) readerBookTitle.textContent = 'Загрузка книги...';
+            }
+        } else if (hash.startsWith('#srs')) {
+            if (dictionaryView) dictionaryView.classList.add('hidden');
+            if (readerView) readerView.classList.add('hidden');
+            if (srsView) srsView.classList.remove('hidden');
+            updateMobileActiveTab('srs');
+        }
+    }
+    applyInitialViewPreflight();
+
     // -----------------------------------------------------------------------
     // Session & Auth Check
     // -----------------------------------------------------------------------
@@ -395,23 +431,8 @@ document.addEventListener('DOMContentLoaded', () => {
                 const data = await resp.json();
                 currentUser = data.user;
                 showApp();
-                await loadInitialData();
+                await handleRouting();
-
+                loadInitialData();
-                // Restore last active view and reading session if page was refreshed
-                try {
-                    const lastView = localStorage.getItem('notes_active_view');
-                    const lastBookId = localStorage.getItem('notes_active_book_id');
-                    if (lastView === 'reader-view') {
-                        openReaderView();
-                        if (lastBookId) {
-                            openBook(parseInt(lastBookId, 10));
-                        }
-                    } else if (lastView === 'srs-view') {
-                        openSrsView();
-                    }
-                } catch (e) {
-                    console.error('State restore error:', e);
-                }
             } else {
                 showLogin();
             }
@@ -454,6 +475,7 @@ document.addEventListener('DOMContentLoaded', () => {
                 }
                 currentUser = data.user;
                 showApp();
+                await handleRouting();
                 loadInitialData();
             } else {
                 loginError.textContent = data.detail || 'Неверный логин или пароль';
@@ -467,8 +489,10 @@ document.addEventListener('DOMContentLoaded', () => {
 
     logoutBtn.addEventListener('click', async () => {
         localStorage.removeItem('notes_token');
-        await fetch('/api/logout', { method: 'POST' });
+        localStorage.removeItem('notes_active_book_id');
+        try { await fetch('/api/logout', { method: 'POST' }); } catch (e) {}
         currentUser = null;
+        window.location.hash = '';
         window.location.reload();
     });
 
@@ -984,18 +1008,14 @@ document.addEventListener('DOMContentLoaded', () => {
     });
 
     // -----------------------------------------------------------------------
-    // Interactive SRS Trainer (5 Modes + Smart Mix)
+    // Interactive SRS Trainer & View Switching (Hash Router Driven)
     // -----------------------------------------------------------------------
     srsTrainerBtn.addEventListener('click', () => {
-        openSrsView();
+        window.location.hash = '#srs';
     });
 
     srsExitBtn.addEventListener('click', () => {
-        closeSrsView();
+        window.location.hash = '#dictionary';
-    });
-
-    navBrandHome.addEventListener('click', () => {
-        closeSrsView();
     });
 
     srsMixBtn.addEventListener('click', () => {
@@ -1028,7 +1048,11 @@ document.addEventListener('DOMContentLoaded', () => {
         if (target) target.classList.add('active');
     }
 
-    function openDictionaryView() {
+    function openDictionaryView(updateHash = true) {
+        if (updateHash && window.location.hash !== '#dictionary') {
+            window.location.hash = '#dictionary';
+            return;
+        }
         srsView.classList.add('hidden');
         if (readerView) readerView.classList.add('hidden');
         dictionaryView.classList.remove('hidden');
@@ -1037,7 +1061,12 @@ document.addEventListener('DOMContentLoaded', () => {
         loadInitialData();
     }
 
-    function openSrsView(tagFilter = null) {
+    function openSrsView(tagFilter = null, updateHash = true) {
+        const targetHash = tagFilter ? `#srs/${encodeURIComponent(tagFilter)}` : '#srs';
+        if (updateHash && window.location.hash !== targetHash) {
+            window.location.hash = targetHash;
+            return;
+        }
         dictionaryView.classList.add('hidden');
         if (readerView) readerView.classList.add('hidden');
         srsView.classList.remove('hidden');
@@ -1047,23 +1076,89 @@ document.addEventListener('DOMContentLoaded', () => {
     }
 
     function closeSrsView() {
-        srsView.classList.add('hidden');
+        openDictionaryView(true);
-        if (readerView) readerView.classList.add('hidden');
-        dictionaryView.classList.remove('hidden');
-        updateMobileActiveTab('dict');
-        try { localStorage.setItem('notes_active_view', 'dictionary-view'); } catch (e) {}
-        loadInitialData();
     }
 
-    function openReaderView() {
+    function openBookshelfView(updateHash = true) {
+        if (updateHash && window.location.hash !== '#reader') {
+            window.location.hash = '#reader';
+            return;
+        }
         dictionaryView.classList.add('hidden');
         srsView.classList.add('hidden');
         if (readerView) readerView.classList.remove('hidden');
+        if (bookshelfContainer) bookshelfContainer.classList.remove('hidden');
+        if (readerInterface) readerInterface.classList.add('hidden');
         updateMobileActiveTab('reader');
-        try { localStorage.setItem('notes_active_view', 'reader-view'); } catch (e) {}
+        try {
+            localStorage.setItem('notes_active_view', 'reader-view');
+            localStorage.removeItem('notes_active_book_id');
+        } catch (e) {}
         loadBookshelf();
     }
 
+    function openReaderView(updateHash = true) {
+        const lastBookId = localStorage.getItem('notes_active_book_id');
+        if (lastBookId) {
+            window.location.hash = `#reader/book/${lastBookId}`;
+        } else {
+            openBookshelfView(updateHash);
+        }
+    }
+
+    let isRouting = false;
+    async function handleRouting() {
+        if (isRouting) return;
+        isRouting = true;
+        try {
+            let hash = window.location.hash || '';
+            if (!hash || hash === '#') {
+                try {
+                    const lastView = localStorage.getItem('notes_active_view');
+                    const lastBookId = localStorage.getItem('notes_active_book_id');
+                    if (lastView === 'reader-view') {
+                        hash = lastBookId ? `#reader/book/${lastBookId}` : '#reader';
+                        window.location.hash = hash;
+                        return;
+                    } else if (lastView === 'srs-view') {
+                        hash = '#srs';
+                        window.location.hash = hash;
+                        return;
+                    } else {
+                        hash = '#dictionary';
+                    }
+                } catch (e) {
+                    hash = '#dictionary';
+                }
+            }
+
+            const cleanHash = hash.replace(/^#\/?/, '');
+
+            if (!cleanHash || cleanHash === 'dictionary') {
+                openDictionaryView(false);
+            } else if (cleanHash.startsWith('srs')) {
+                const parts = cleanHash.split('/');
+                const tag = parts.length > 1 ? decodeURIComponent(parts.slice(1).join('/')) : null;
+                openSrsView(tag, false);
+            } else if (cleanHash.startsWith('reader') || cleanHash === 'bookshelf') {
+                const parts = cleanHash.split('/');
+                if (parts[1] === 'book' && parts[2]) {
+                    const bookId = parseInt(parts[2], 10);
+                    const chIdx = (parts[3] === 'ch' && parts[4] !== undefined) ? parseInt(parts[4], 10) : null;
+                    await openBook(bookId, chIdx, false);
+                } else {
+                    openBookshelfView(false);
+                }
+            } else {
+                openDictionaryView(false);
+            }
+        } finally {
+            isRouting = false;
+        }
+    }
+
+    window.addEventListener('hashchange', handleRouting);
+
     function initMobileNavigation() {
         const tabDict = document.getElementById('tab-nav-dict');
         const tabSrs = document.getElementById('tab-nav-srs');
@@ -1081,9 +1176,9 @@ document.addEventListener('DOMContentLoaded', () => {
         const mobileThemeBtn = document.getElementById('mobile-theme-btn');
         const mobileLogoutBtn = document.getElementById('mobile-logout-btn');
 
-        if (tabDict) tabDict.addEventListener('click', () => openDictionaryView());
+        if (tabDict) tabDict.addEventListener('click', () => { window.location.hash = '#dictionary'; });
-        if (tabSrs) tabSrs.addEventListener('click', () => openSrsView());
+        if (tabSrs) tabSrs.addEventListener('click', () => { window.location.hash = '#srs'; });
-        if (tabReader) tabReader.addEventListener('click', () => openReaderView());
+        if (tabReader) tabReader.addEventListener('click', () => { window.location.hash = '#reader'; });
 
         if (tabStats) {
             tabStats.addEventListener('click', () => {
@@ -1158,8 +1253,8 @@ document.addEventListener('DOMContentLoaded', () => {
         }
     }
 
-    navBrandHome.addEventListener('click', () => openDictionaryView());
+    navBrandHome.addEventListener('click', () => { window.location.hash = '#dictionary'; });
-    if (navReaderBtn) navReaderBtn.addEventListener('click', () => openReaderView());
+    if (navReaderBtn) navReaderBtn.addEventListener('click', () => { window.location.hash = '#reader'; });
     initMobileNavigation();
 
     async function startSrsTrainingSession(forceAll = false, tagFilter = null) {
@@ -1931,8 +2026,10 @@ document.addEventListener('DOMContentLoaded', () => {
 
     async function loadBookshelf() {
         if (!bookshelfContainer) return;
-        bookshelfContainer.classList.remove('hidden');
+        if (!window.location.hash.includes('/book/')) {
-        if (readerInterface) readerInterface.classList.add('hidden');
+            bookshelfContainer.classList.remove('hidden');
+            if (readerInterface) readerInterface.classList.add('hidden');
+        }
         if (bookshelfGrid) bookshelfGrid.innerHTML = '';
         if (bookshelfEmpty) bookshelfEmpty.classList.add('hidden');
 
@@ -1958,9 +2055,17 @@ document.addEventListener('DOMContentLoaded', () => {
             const card = document.createElement('div');
             card.className = 'book-card';
 
-            const totalCh = b.chapters_count || 1;
+            const totalCh = Math.max(1, b.chapters_count || 1);
-            const currentCh = (b.current_chapter || 0) + 1;
+            const chIndex = Math.max(0, Math.min(totalCh - 1, b.current_chapter || 0));
-            const pct = Math.min(100, Math.round((currentCh / totalCh) * 100));
+            const pos = (typeof b.current_position === 'number') ? Math.max(0, Math.min(1.0, b.current_position)) : 0.0;
+
+            const progressFraction = (chIndex + pos) / totalCh;
+            const totalPct = Math.min(100, Math.max(0, Math.round(progressFraction * 100)));
+            const chPct = Math.min(100, Math.max(0, Math.round(pos * 100)));
+
+            const progressLabels = totalCh === 1
+                ? `<span>1 глава • ${totalPct}%</span><span>${totalPct}%</span>`
+                : `<span>Глава ${chIndex + 1} из ${totalCh} (${chPct}%)</span><span>${totalPct}%</span>`;
 
             card.innerHTML = `
                 <div>
@@ -1977,11 +2082,10 @@ document.addEventListener('DOMContentLoaded', () => {
                     </div>
                     <div class="book-progress-wrap">
                         <div class="book-progress-labels">
-                            <span>Глава ${currentCh} из ${totalCh}</span>
+                            ${progressLabels}
-                            <span>${pct}%</span>
                         </div>
                         <div class="book-progress-bar-bg">
-                            <div class="book-progress-bar-fill" style="width: ${pct}%"></div>
+                            <div class="book-progress-bar-fill" style="width: ${totalPct}%"></div>
                         </div>
                     </div>
                 </div>
@@ -1992,10 +2096,12 @@ document.addEventListener('DOMContentLoaded', () => {
                 </div>
             `;
 
-            card.querySelector('.read-book-btn').addEventListener('click', () => openBook(b.id));
+            card.querySelector('.read-book-btn').addEventListener('click', () => {
+                window.location.hash = `#reader/book/${b.id}`;
+            });
             card.querySelector('.train-book-btn').addEventListener('click', () => {
                 const bookTag = slugify(b.title);
-                openSrsView(bookTag);
+                window.location.hash = `#srs/${encodeURIComponent(bookTag)}`;
             });
             card.querySelector('.delete-book-btn').addEventListener('click', async () => {
                 if (confirm(`Удалить книгу "${b.title}" из библиотеки?`)) {
@@ -2008,16 +2114,46 @@ document.addEventListener('DOMContentLoaded', () => {
         });
     }
 
-    async function openBook(bookId) {
+    async function openBook(bookId, specificChapterIdx = null, updateHash = true) {
+        if (!bookId) return;
+
+        if (readerView) readerView.classList.remove('hidden');
+        if (dictionaryView) dictionaryView.classList.add('hidden');
+        if (srsView) srsView.classList.add('hidden');
+        if (bookshelfContainer) bookshelfContainer.classList.add('hidden');
+        if (readerInterface) readerInterface.classList.remove('hidden');
+        updateMobileActiveTab('reader');
+
+        if (currentBook && currentBook.id === bookId) {
+            if (specificChapterIdx !== null && specificChapterIdx !== undefined && !isNaN(specificChapterIdx)) {
+                if (specificChapterIdx !== currentChapterIndex) {
+                    renderChapter(specificChapterIdx, 0, 0, 0);
+                }
+            }
+            if (updateHash) {
+                const desiredHash = `#reader/book/${bookId}/ch/${currentChapterIndex}`;
+                if (window.location.hash !== desiredHash) {
+                    history.replaceState(null, '', desiredHash);
+                }
+            }
+            return;
+        }
+
         try {
+            if (readerBookTitle) readerBookTitle.textContent = 'Загрузка книги...';
             const resp = await fetch(`/api/books/${bookId}`);
-            if (!resp.ok) return alert('Не удалось открыть книгу');
+            if (!resp.ok) {
+                alert('Не удалось открыть книгу');
+                window.location.hash = '#reader';
+                return;
+            }
             currentBook = await resp.json();
 
             // Load saved reading position from localStorage or server
             let targetChapter = currentBook.current_chapter || 0;
             let targetScrollTop = null;
             let targetFraction = currentBook.current_position || 0;
+            let targetAnchorIdx = null;
 
             try {
                 const raw = localStorage.getItem(`notes_book_${bookId}_pos`);
@@ -2027,27 +2163,36 @@ document.addEventListener('DOMContentLoaded', () => {
                         targetChapter = parsed.chapter;
                         targetScrollTop = parsed.scrollTop;
                         targetFraction = parsed.fraction;
+                        targetAnchorIdx = parsed.anchorIdx;
                     }
                 }
             } catch (e) {}
 
-            currentChapterIndex = targetChapter;
+            if (specificChapterIdx !== null && specificChapterIdx !== undefined && !isNaN(specificChapterIdx)) {
+                targetChapter = specificChapterIdx;
+                if (specificChapterIdx !== (currentBook.current_chapter || 0)) {
+                    targetScrollTop = 0;
+                    targetFraction = 0;
+                    targetAnchorIdx = 0;
+                }
+            }
+
+            currentChapterIndex = Math.max(0, Math.min(targetChapter, (currentBook.chapters ? currentBook.chapters.length - 1 : 0)));
 
             readerBookTitle.textContent = currentBook.title;
             readerBookAuthor.textContent = currentBook.author || '';
 
-            // Populate chapter selector
+            // Populate chapter selector with visual status markers
             readerChapterSelect.innerHTML = '';
             const chapters = currentBook.chapters || [];
             chapters.forEach((ch, idx) => {
                 const opt = document.createElement('option');
                 opt.value = idx;
-                opt.textContent = ch.title || `Глава ${idx + 1}`;
+                const statusIcon = idx < currentChapterIndex ? '✔ ' : (idx === currentChapterIndex ? '▶ ' : '○ ');
+                opt.textContent = `${statusIcon}${ch.title || `Глава ${idx + 1}`}`;
                 readerChapterSelect.appendChild(opt);
             });
 
-            bookshelfContainer.classList.add('hidden');
-            readerInterface.classList.remove('hidden');
             applyReaderSettings();
 
             try {
@@ -2055,17 +2200,33 @@ document.addEventListener('DOMContentLoaded', () => {
                 localStorage.setItem('notes_active_view', 'reader-view');
             } catch (e) {}
 
-            renderChapter(currentChapterIndex, targetScrollTop, targetFraction);
+            if (updateHash) {
+                const desiredHash = `#reader/book/${bookId}/ch/${currentChapterIndex}`;
+                if (window.location.hash !== desiredHash) {
+                    history.replaceState(null, '', desiredHash);
+                }
+            }
+
+            renderChapter(currentChapterIndex, targetScrollTop, targetFraction, targetAnchorIdx);
         } catch (e) {
             console.error('Error opening book:', e);
         }
     }
 
-    function renderChapter(index, restoreScrollTop = null, restoreFraction = null) {
+    function renderChapter(index, restoreScrollTop = null, restoreFraction = null, restoreAnchorIdx = null) {
         if (!currentBook || !currentBook.chapters) return;
         currentChapterIndex = Math.max(0, Math.min(index, currentBook.chapters.length - 1));
         readerChapterSelect.value = currentChapterIndex;
 
+        // Refresh status icons in chapter select
+        if (readerChapterSelect.options) {
+            for (let i = 0; i < readerChapterSelect.options.length; i++) {
+                const rawTitle = currentBook.chapters[i]?.title || `Глава ${i + 1}`;
+                const icon = i < currentChapterIndex ? '✔ ' : (i === currentChapterIndex ? '▶ ' : '○ ');
+                readerChapterSelect.options[i].textContent = `${icon}${rawTitle}`;
+            }
+        }
+
         readerPrevChBtn.disabled = currentChapterIndex <= 0;
         readerNextChBtn.disabled = currentChapterIndex >= currentBook.chapters.length - 1;
 
@@ -2075,6 +2236,7 @@ document.addEventListener('DOMContentLoaded', () => {
         if (chapter.title) {
             const h = document.createElement('h2');
             h.textContent = chapter.title;
+            h.setAttribute('data-block-idx', '0');
             readerContentBody.appendChild(h);
         }
 
@@ -2087,10 +2249,13 @@ document.addEventListener('DOMContentLoaded', () => {
         // Parse content into structured blocks (code, headings, lists, quotes, paragraphs)
         const blocks = parseContentBlocks(chapter.content);
 
-        blocks.forEach(block => {
+        blocks.forEach((block, blockIdx) => {
+            const domIdx = blockIdx + 1;
+            let blockEl = null;
+
             if (block.type === 'code') {
-                const codeBlock = document.createElement('div');
+                blockEl = document.createElement('div');
-                codeBlock.className = 'reader-code-block';
+                blockEl.className = 'reader-code-block';
 
                 const header = document.createElement('div');
                 header.className = 'reader-code-header';
@@ -2123,12 +2288,11 @@ document.addEventListener('DOMContentLoaded', () => {
                 codeEl.textContent = block.code;
                 pre.appendChild(codeEl);
 
-                codeBlock.appendChild(header);
+                blockEl.appendChild(header);
-                codeBlock.appendChild(pre);
+                blockEl.appendChild(pre);
-                readerContentBody.appendChild(codeBlock);
             } else if (block.type === 'table') {
-                const wrap = document.createElement('div');
+                blockEl = document.createElement('div');
-                wrap.className = 'reader-table-wrap';
+                blockEl.className = 'reader-table-wrap';
                 const table = document.createElement('table');
                 table.className = 'reader-table';
 
@@ -2163,42 +2327,52 @@ document.addEventListener('DOMContentLoaded', () => {
                     });
                     table.appendChild(tbody);
                 }
-                wrap.appendChild(table);
+                blockEl.appendChild(table);
-                readerContentBody.appendChild(wrap);
             } else if (block.type === 'heading') {
                 const tag = `h${Math.min(4, Math.max(1, block.level || 2))}`;
-                const h = document.createElement(tag);
+                blockEl = document.createElement(tag);
-                if (block.align) h.style.textAlign = block.align;
+                if (block.align) blockEl.style.textAlign = block.align;
-                renderInteractiveSpans(h, block.text, block.text, knownWordsMap);
+                renderInteractiveSpans(blockEl, block.text, block.text, knownWordsMap);
-                readerContentBody.appendChild(h);
             } else if (block.type === 'blockquote') {
-                const bq = document.createElement('blockquote');
+                blockEl = document.createElement('blockquote');
-                renderInteractiveSpans(bq, block.text, block.text, knownWordsMap);
+                renderInteractiveSpans(blockEl, block.text, block.text, knownWordsMap);
-                readerContentBody.appendChild(bq);
             } else if (block.type === 'ul' || block.type === 'ol') {
-                const listEl = document.createElement(block.type);
+                blockEl = document.createElement(block.type);
                 block.items.forEach(itemText => {
                     const li = document.createElement('li');
                     renderInteractiveSpans(li, itemText, itemText, knownWordsMap);
-                    listEl.appendChild(li);
+                    blockEl.appendChild(li);
                 });
-                readerContentBody.appendChild(listEl);
             } else if (block.type === 'hr') {
-                readerContentBody.appendChild(document.createElement('hr'));
+                blockEl = document.createElement('hr');
             } else {
                 // paragraph
-                const p = document.createElement('p');
+                blockEl = document.createElement('p');
                 if (block.align) {
-                    p.style.textAlign = block.align;
+                    blockEl.style.textAlign = block.align;
-                    p.classList.add('text-center');
+                    blockEl.classList.add('text-center');
                 }
-                renderInteractiveSpans(p, block.text, block.text, knownWordsMap);
+                renderInteractiveSpans(blockEl, block.text, block.text, knownWordsMap);
-                readerContentBody.appendChild(p);
+            }
+
+            if (blockEl) {
+                blockEl.setAttribute('data-block-idx', domIdx.toString());
+                readerContentBody.appendChild(blockEl);
             }
         });
 
         function applyScroll() {
             if (!readerScrollArea) return;
+            if (restoreAnchorIdx !== null && restoreAnchorIdx !== undefined) {
+                const el = readerContentBody.querySelector(`[data-block-idx="${restoreAnchorIdx}"]`);
+                if (el) {
+                    const containerTop = readerScrollArea.getBoundingClientRect().top;
+                    const elTop = el.getBoundingClientRect().top;
+                    readerScrollArea.scrollTop += (elTop - containerTop - 10);
+                    updateReaderProgressBar();
+                    return;
+                }
+            }
             if (restoreScrollTop !== null && restoreScrollTop > 0) {
                 readerScrollArea.scrollTop = restoreScrollTop;
             } else if (restoreFraction !== null && restoreFraction > 0) {
@@ -2880,37 +3054,39 @@ document.addEventListener('DOMContentLoaded', () => {
         });
     }
 
-    // Chapter Navigation & Reader Toolbar
+    // Chapter Navigation & Reader Toolbar (URL Hash Driven)
     if (readerChapterSelect) {
         readerChapterSelect.addEventListener('change', () => {
-            renderChapter(parseInt(readerChapterSelect.value, 10), 0, 0);
+            const ch = parseInt(readerChapterSelect.value, 10);
+            if (currentBook) {
+                window.location.hash = `#reader/book/${currentBook.id}/ch/${ch}`;
+            }
         });
     }
 
     if (readerPrevChBtn) {
         readerPrevChBtn.addEventListener('click', () => {
-            if (currentChapterIndex > 0) renderChapter(currentChapterIndex - 1, 0, 0);
+            if (currentBook && currentChapterIndex > 0) {
+                window.location.hash = `#reader/book/${currentBook.id}/ch/${currentChapterIndex - 1}`;
+            }
         });
     }
 
     if (readerNextChBtn) {
         readerNextChBtn.addEventListener('click', () => {
-            if (currentBook && currentChapterIndex < currentBook.chapters.length - 1) {
+            if (currentBook && currentBook.chapters && currentChapterIndex < currentBook.chapters.length - 1) {
-                renderChapter(currentChapterIndex + 1, 0, 0);
+                window.location.hash = `#reader/book/${currentBook.id}/ch/${currentChapterIndex + 1}`;
             }
         });
     }
 
     if (readerBackBtn) {
         readerBackBtn.addEventListener('click', () => {
-            readerInterface.classList.add('hidden');
+            window.location.hash = '#reader';
-            bookshelfContainer.classList.remove('hidden');
-            try { localStorage.removeItem('notes_active_book_id'); } catch (e) {}
-            loadBookshelf();
         });
     }
 
-    // Scroll Position Tracking & Real-Time Chapter Progress
+    // Scroll Position Tracking, Paragraph Anchoring & Real-Time Weighted Progress
     let readerScrollSaveTimer = null;
 
     function getReaderScrollMetrics() {
@@ -2922,12 +3098,36 @@ document.addEventListener('DOMContentLoaded', () => {
         return { scrollTop, maxScroll, pct, fraction };
     }
 
+    function getActiveAnchorIndex() {
+        if (!readerScrollArea || !readerContentBody) return null;
+        const blocks = readerContentBody.querySelectorAll('[data-block-idx]');
+        if (!blocks || blocks.length === 0) return null;
+        const containerTop = readerScrollArea.getBoundingClientRect().top;
+        for (let el of blocks) {
+            const rect = el.getBoundingClientRect();
+            if (rect.bottom >= containerTop + 10) {
+                return parseInt(el.getAttribute('data-block-idx'), 10);
+            }
+        }
+        return 0;
+    }
+
     function updateReaderProgressBar() {
-        const { pct } = getReaderScrollMetrics();
+        const { pct, fraction } = getReaderScrollMetrics();
         if (readerChapterProgressFill) {
             readerChapterProgressFill.style.width = `${pct}%`;
         }
-        if (readerScrollPctBadge) {
+
+        if (currentBook) {
+            const totalCh = Math.max(1, (currentBook.chapters ? currentBook.chapters.length : 1));
+            const overallFraction = (currentChapterIndex + fraction) / totalCh;
+            const totalPct = Math.min(100, Math.max(0, Math.round(overallFraction * 100)));
+
+            if (readerScrollPctBadge) {
+                readerScrollPctBadge.textContent = `${pct}%`;
+                readerScrollPctBadge.title = `Глава ${currentChapterIndex + 1}/${totalCh}: ${pct}% • Вся книга: ${totalPct}%`;
+            }
+        } else if (readerScrollPctBadge) {
             readerScrollPctBadge.textContent = `${pct}%`;
         }
     }
@@ -2937,6 +3137,7 @@ document.addEventListener('DOMContentLoaded', () => {
         updateReaderProgressBar();
 
         const { scrollTop, fraction } = getReaderScrollMetrics();
+        const anchorIdx = getActiveAnchorIndex();
 
         // 1. Instant local persistence
         try {
@@ -2945,6 +3146,7 @@ document.addEventListener('DOMContentLoaded', () => {
                 chapter: currentChapterIndex,
                 scrollTop: scrollTop,
                 fraction: fraction,
+                anchorIdx: anchorIdx,
                 savedAt: Date.now()
             }));
             localStorage.setItem('notes_active_book_id', currentBook.id);
@@ -2970,11 +3172,13 @@ document.addEventListener('DOMContentLoaded', () => {
     window.addEventListener('beforeunload', () => {
         if (currentBook && readerScrollArea) {
             const { scrollTop, fraction } = getReaderScrollMetrics();
+            const anchorIdx = getActiveAnchorIndex();
             try {
                 localStorage.setItem(`notes_book_${currentBook.id}_pos`, JSON.stringify({
                     chapter: currentChapterIndex,
                     scrollTop: scrollTop,
                     fraction: fraction,
+                    anchorIdx: anchorIdx,
                     savedAt: Date.now()
                 }));
                 localStorage.setItem('notes_active_book_id', currentBook.id);
@@ -3003,6 +3207,7 @@ document.addEventListener('DOMContentLoaded', () => {
 
     function applyReaderSettings() {
         if (!readerScrollArea) return;
+        const anchorIdx = getActiveAnchorIndex();
 
         // 1. Font size
         readerScrollArea.style.setProperty('--reader-font-size', `${readerSettings.fontSize}px`);
@@ -3028,6 +3233,18 @@ document.addEventListener('DOMContentLoaded', () => {
         readerScrollArea.classList.add(`reader-align-${readerSettings.textAlign}`);
 
         updateReaderSettingsUI();
+
+        // Re-anchor scroll position after font/layout change
+        if (anchorIdx !== null && anchorIdx !== undefined) {
+            requestAnimationFrame(() => {
+                const el = readerContentBody.querySelector(`[data-block-idx="${anchorIdx}"]`);
+                if (el) {
+                    const containerTop = readerScrollArea.getBoundingClientRect().top;
+                    const elTop = el.getBoundingClientRect().top;
+                    readerScrollArea.scrollTop += (elTop - containerTop - 10);
+                }
+            });
+        }
     }
 
     function updateReaderSettingsUI() {
@@ -3220,7 +3437,7 @@ document.addEventListener('DOMContentLoaded', () => {
         readerTrainBtn.addEventListener('click', () => {
             if (currentBook) {
                 const bookTag = slugify(currentBook.title);
-                openSrsView(bookTag);
+                window.location.hash = `#srs/${encodeURIComponent(bookTag)}`;
             }
         });
     }
@@ -3260,8 +3477,7 @@ document.addEventListener('DOMContentLoaded', () => {
                 if (resp.ok) {
                     const book = await resp.json();
                     addBookModal.classList.add('hidden');
-                    await loadBookshelf();
+                    window.location.hash = `#reader/book/${book.id}`;
-                    openBook(book.id);
                 } else {
                     alert('Ошибка при сохранении книги');
                 }
@@ -3288,8 +3504,7 @@ document.addEventListener('DOMContentLoaded', () => {
                 if (resp.ok) {
                     const book = await resp.json();
                     bookFileInput.value = '';
-                    await loadBookshelf();
+                    window.location.hash = `#reader/book/${book.id}`;
-                    openBook(book.id);
                 } else {
                     const errData = await resp.json();
                     alert(`Ошибка загрузки: ${errData.detail || 'Не удалось обработать файл'}`);

tests/test_api.py

@@ -594,6 +594,29 @@ Nearly ten years had passed.
     assert "Chapter 1" in chs[0]["title"]
     assert "Chapter 2" in chs[1]["title"]
 
+    # 3b. Smart chapter detection: word-spelled (CHAPTER ONE), numbered sections, ALL CAPS, bold
+    smart_txt = """Some intro notes before starting.
+
+CHAPTER ONE: THE BEGINNING
+It was a cold day in April.
+
+1.1 Network Fundamentals
+Devices communicate over IP.
+
+**Key Architecture**
+The architecture is modular.
+
+CONCLUSION AND NEXT STEPS
+Final thoughts on the topic.
+"""
+    st_title, st_auth, st_chs = parse_text(smart_txt, title="Smart Book")
+    assert len(st_chs) >= 4
+    titles = [c["title"] for c in st_chs]
+    assert any("CHAPTER ONE" in t for t in titles)
+    assert any("1.1 Network Fundamentals" in t for t in titles)
+    assert any("Key Architecture" in t for t in titles)
+    assert any("CONCLUSION AND NEXT STEPS" in t for t in titles)
+
     # 4. parse_text chunking on long text
     long_words = ["word"] * 7000
     long_text = "\n\n".join([" ".join(long_words[i:i + 400]) for i in range(0, len(long_words), 400)])