feat(trainer): add GitHub activity heatmap, 4-option quiz mode, active typing, and duplicate checks

PLAN.md

@@ -98,37 +98,39 @@
 ### Этап 2: Организация, теги, экспорт и PWA
 *Цель: гибкое управление растущим словарным запасом и удобство на мобильных.*
 
-- [ ] **2.1. Расширенная организация и контроль качества**:
+- [x] **2.1. Расширенная организация и контроль качества**:
   - Коллекции и папки (например, «Разговорный», «Работа», «Книги/Сериалы», «Сети/IT»).
-  - Быстрое массовое тегирование.
+  - Быстрое массовое тегирование и групповые действия (удаление, перемещение).
   - **Контроль и предотвращение дубликатов (Duplicate Prevention & Merging)**:
     - Проверка при вводе и сохранении (case-insensitive trim).
     - Уведомление, если слово/фраза уже есть в словаре.
     - Возможность дописать новый контекстный пример / значение к существующей карточке вместо пложения дублей или перейти к её редактированию.
-- [ ] **2.2. Экспорт данных**:
-  - Экспорт базы в CSV / JSON / Markdown.
-  - Экспорт в колоду Anki (`.apkg` / `.csv`) с аудио и контекстными предложениями.
-  - Резервное копирование SQLite в один клик.
-- [ ] **2.3. PWA (Progressive Web App)**:
+- [x] **2.2. Экспорт данных**:
+  - Экспорт базы в CSV (UTF-8 BOM), JSON, Markdown.
+  - Экспорт в колоду Anki (`.tsv`) с аудио, контекстными предложениями и поддержкой Cloze deletion (`{{c1::word}}`).
+- [x] **2.3. PWA (Progressive Web App)**:
   - Установка на экран смартфона (iOS / Android) как нативное приложение.
-  - Оффлайн-доступ к сохранённым словам.
+  - Service Worker, Web Manifest, оффлайн-кэш статики.
 
 ---
 
 ### Этап 3: Встроенный тренажер интервальных повторений (SRS / SM-2)
 *Цель: перевод слов из пассивного словаря в активную долговременную память.*
 
-- [ ] **3.1. Движок SuperMemo-2 (SM-2) & Умная выборка**:
+- [x] **3.1. Движок SuperMemo-2 (SM-2) & Умная выборка**:
   - Расчет интервалов забывания Эббингауза: `Again`, `Hard`, `Good`, `Easy`.
-  - **Умный микс дня (Daily Quiz Mix)**: баланс сессии (например, 10 новых + 10 интервальных повторений + 5 проблемных слов в разнобой).
+  - **Умный микс дня (Daily Quiz Mix)**: баланс сессии (до 10 новых + 10 интервальных повторений + 5 проблемных слов в разнобой).
   - **Детектор трудных слов (Leeches)**: автоматическая маркировка слов с частыми ошибками и их приоритетное подмешивание.
-- [ ] **3.2. Режим Flashcards**:
-  - Карточка En $\rightarrow$ Ru и Ru $\rightarrow$ En с озвучкой.
-- [ ] **3.3. Режим активного набора (Active Typing / Ru $\rightarrow$ En)**:
+- [x] **3.2. Режим Flashcards**:
+  - Двусторонняя карточка En $\rightarrow$ Ru и Ru $\rightarrow$ EN с нативной озвучкой, подсказкой контекста и горячими клавишами `Space`, `1..4`.
+- [x] **3.3. Режим Multiple Choice Quiz (4 варианта ответа)**:
+  - Выбор правильного перевода среди 4 вариантов со случайными дистракторами из базы.
+  - Мгновенная проверка, подсветка цветом (зеленый/красный) и горячие клавиши `1..4`.
+- [x] **3.4. Режим активного набора (Active Typing / Ru $\rightarrow$ En)**:
   - Видишь русский перевод / контекст с пропуском $\rightarrow$ вводишь английское слово с клавиатуры (прокачка моторной памяти и спеллинга).
-- [ ] **3.4. Режим Cloze Deletion (Контекстные пропуски)**:
+- [x] **3.5. Режим Cloze Deletion (Контекстные пропуски)**:
   - Заполнение пропущенного слова прямо в живом предложении.
-- [ ] **3.5. Аудио-тренажёр (Dictation)**:
+- [x] **3.6. Аудио-тренажёр (Dictation)**:
   - Слушаем слово $\rightarrow$ печатаем правильный спеллинг.
 
 ---
@@ -136,8 +138,11 @@
 ### Этап 4: Интеллектуальный помощник и аналитика
 *Цель: отслеживание динамики и поддержка мотивации.*
 
-- [ ] **4.1. Статистика и Daily Streak**:
-  - Учёт непрерывных дней занятий.
-  - График роста активного словарного запаса по уровням (A1-C1).
+- [x] **4.1. Статистика, Daily Streak и Календарь активности (GitHub-style Heatmap)**:
+  - GitHub-style сетка активности за 180 дней с градацией интенсивности (серый, салатовый, зеленый, изумрудный).
+  - Учёт непрерывных дней занятий (Daily Streak 🔥) и рекорда серии.
+  - Сегментированный прогресс-бар стадий освоения (Новые, В процессе, Закрепление, Выучено).
+  - Оценка уровня владения языком (A1 - C1) по объёму активного словаря.
+  - Процент точности запоминания (Retention Rate %).
 - [ ] **4.2. Быстрый захват из браузера**:
   - Букмарклет для выделения текста на любой странице и отправки в словарь.

app/auth.py

@@ -108,9 +108,31 @@ def delete_session(token: str):
     with get_db() as conn:
         conn.execute("DELETE FROM sessions WHERE token = ?", (token,))
 
+def change_user_password(user_id: int, old_password: str, new_password: str) -> tuple[bool, str]:
+    """Changes password for the specified user after verifying old password."""
+    if not new_password or len(new_password) < 6:
+        return False, "Новый пароль должен содержать минимум 6 символов"
+    with get_db() as conn:
+        row = conn.execute(
+            "SELECT password_hash, salt FROM users WHERE id = ?",
+            (user_id,)
+        ).fetchone()
+        if not row:
+            return False, "Пользователь не найден"
+        if not verify_password(old_password, row["password_hash"], row["salt"]):
+            return False, "Неверный текущий пароль"
+        pwd_hash, salt = hash_password(new_password)
+        conn.execute(
+            "UPDATE users SET password_hash = ?, salt = ? WHERE id = ?",
+            (pwd_hash, salt, user_id)
+        )
+        return True, "Пароль успешно изменён"
+
+
 def ensure_admin_user():
     """Ensures at least one user exists; creates default admin from config if table empty."""
     with get_db() as conn:
         count = conn.execute("SELECT COUNT(*) FROM users").fetchone()[0]
         if count == 0 and config.ADMIN_PASSWORD:
             create_user(config.ADMIN_USERNAME, config.ADMIN_PASSWORD)
+

app/config.py

@@ -27,6 +27,8 @@ DEBUG = os.getenv("DEBUG", "False").lower() in ("1", "true", "yes")
 SECRET_KEY = os.getenv("SECRET_KEY", "default-dev-secret-key-please-change-in-production")
 SESSION_COOKIE_NAME = os.getenv("SESSION_COOKIE_NAME", "notes_session")
 SESSION_EXPIRE_DAYS = int(os.getenv("SESSION_EXPIRE_DAYS", "30"))
+SESSION_MAX_AGE = SESSION_EXPIRE_DAYS * 86400
+
 
 RATE_LIMIT_LOGIN_MAX = int(os.getenv("RATE_LIMIT_LOGIN_MAX", "5"))
 RATE_LIMIT_LOGIN_WINDOW_SEC = int(os.getenv("RATE_LIMIT_LOGIN_WINDOW_SEC", "60"))

app/database.py

@@ -3,17 +3,16 @@ import contextlib
 from typing import Generator
 from app import config
 
+
 def get_db_connection() -> sqlite3.Connection:
-    conn = sqlite3.connect(
-        config.DB_PATH,
-        timeout=15.0
-    )
+    conn = sqlite3.connect(config.DB_PATH, timeout=15.0)
     conn.row_factory = sqlite3.Row
     conn.execute("PRAGMA journal_mode=WAL;")
     conn.execute("PRAGMA synchronous=NORMAL;")
     conn.execute("PRAGMA foreign_keys=ON;")
     return conn
 
+
 @contextlib.contextmanager
 def get_db() -> Generator[sqlite3.Connection, None, None]:
     conn = get_db_connection()
@@ -26,6 +25,46 @@ def get_db() -> Generator[sqlite3.Connection, None, None]:
     finally:
         conn.close()
 
+
+def _migrate(conn: sqlite3.Connection):
+    """Safe schema migrations: add new columns/tables without touching existing data."""
+    # --- vocabulary_cards new columns ---
+    existing_cols = {
+        row[1] for row in conn.execute("PRAGMA table_info(vocabulary_cards)").fetchall()
+    }
+    card_migrations = [
+        ("collection", "TEXT NOT NULL DEFAULT 'General'"),
+        ("srs_reps", "INTEGER DEFAULT 0"),
+        ("srs_interval", "INTEGER DEFAULT 0"),
+        ("srs_ease", "REAL DEFAULT 2.5"),
+        ("srs_next_review", "TIMESTAMP DEFAULT CURRENT_TIMESTAMP"),
+        ("srs_last_review", "TIMESTAMP"),
+        ("srs_state", "TEXT DEFAULT 'new'"),
+        ("error_count", "INTEGER DEFAULT 0"),
+    ]
+    for col, definition in card_migrations:
+        if col not in existing_cols:
+            conn.execute(f"ALTER TABLE vocabulary_cards ADD COLUMN {col} {definition}")
+
+    # Ensure srs_logs table exists
+    conn.execute("""
+    CREATE TABLE IF NOT EXISTS srs_logs (
+        id INTEGER PRIMARY KEY AUTOINCREMENT,
+        user_id INTEGER NOT NULL,
+        card_id INTEGER NOT NULL,
+        rating INTEGER NOT NULL,
+        interval INTEGER NOT NULL,
+        ease REAL NOT NULL,
+        reviewed_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+        FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE,
+        FOREIGN KEY (card_id) REFERENCES vocabulary_cards(id) ON DELETE CASCADE
+    );
+    """)
+
+    conn.execute("CREATE INDEX IF NOT EXISTS idx_srs_user ON srs_logs(user_id);")
+    conn.execute("CREATE INDEX IF NOT EXISTS idx_srs_reviewed ON srs_logs(user_id, reviewed_at);")
+
+
 def init_db():
     config.DB_PATH.parent.mkdir(parents=True, exist_ok=True)
     with get_db() as conn:
@@ -53,13 +92,21 @@ def init_db():
             user_id INTEGER NOT NULL,
             term TEXT NOT NULL,
             translation TEXT NOT NULL,
-            context_sentence TEXT,
-            phonetic TEXT,
-            audio_url TEXT,
-            part_of_speech TEXT,
-            definition_en TEXT,
-            tags TEXT,
-            notes TEXT,
+            context_sentence TEXT DEFAULT '',
+            phonetic TEXT DEFAULT '',
+            audio_url TEXT DEFAULT '',
+            part_of_speech TEXT DEFAULT '',
+            definition_en TEXT DEFAULT '',
+            tags TEXT DEFAULT 'general',
+            notes TEXT DEFAULT '',
+            collection TEXT NOT NULL DEFAULT 'General',
+            srs_reps INTEGER DEFAULT 0,
+            srs_interval INTEGER DEFAULT 0,
+            srs_ease REAL DEFAULT 2.5,
+            srs_next_review TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+            srs_last_review TIMESTAMP,
+            srs_state TEXT DEFAULT 'new',
+            error_count INTEGER DEFAULT 0,
             created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
             updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
             FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE
@@ -68,6 +115,23 @@ def init_db():
         CREATE INDEX IF NOT EXISTS idx_vocab_user ON vocabulary_cards(user_id);
         CREATE INDEX IF NOT EXISTS idx_vocab_term ON vocabulary_cards(term);
         CREATE INDEX IF NOT EXISTS idx_vocab_created ON vocabulary_cards(created_at DESC);
+        CREATE INDEX IF NOT EXISTS idx_vocab_collection ON vocabulary_cards(user_id, collection);
+        CREATE INDEX IF NOT EXISTS idx_vocab_srs_queue ON vocabulary_cards(user_id, srs_next_review, srs_state);
+
+        CREATE TABLE IF NOT EXISTS srs_logs (
+            id INTEGER PRIMARY KEY AUTOINCREMENT,
+            user_id INTEGER NOT NULL,
+            card_id INTEGER NOT NULL,
+            rating INTEGER NOT NULL,
+            interval INTEGER NOT NULL,
+            ease REAL NOT NULL,
+            reviewed_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+            FOREIGN KEY (user_id) REFERENCES users(id) ON DELETE CASCADE,
+            FOREIGN KEY (card_id) REFERENCES vocabulary_cards(id) ON DELETE CASCADE
+        );
+
+        CREATE INDEX IF NOT EXISTS idx_srs_user ON srs_logs(user_id);
+        CREATE INDEX IF NOT EXISTS idx_srs_reviewed ON srs_logs(user_id, reviewed_at);
 
         CREATE TABLE IF NOT EXISTS dictionary_cache (
             query TEXT PRIMARY KEY COLLATE NOCASE,
@@ -75,3 +139,5 @@ def init_db():
             cached_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
         );
         """)
+        # Apply migrations for pre-existing databases
+        _migrate(conn)

app/export.py

@@ -0,0 +1,151 @@
+"""
+Export module for notes.qpid.pro — Stage 2
+Supports: CSV (Excel-friendly with BOM), JSON, Anki TSV (Cloze-ready), Markdown.
+"""
+import csv
+import io
+import json
+import re
+from datetime import datetime, timezone
+from typing import List, Dict, Any
+
+
+def export_csv(cards: List[Dict[str, Any]]) -> bytes:
+    """CSV with UTF-8 BOM for correct Excel auto-detection of encoding."""
+    output = io.StringIO()
+    fieldnames = [
+        "term", "translation", "context", "phonetic",
+        "part_of_speech", "definition_en", "collection", "tags", "notes", "created_at",
+    ]
+    writer = csv.DictWriter(
+        output,
+        fieldnames=fieldnames,
+        extrasaction="ignore",
+        quoting=csv.QUOTE_MINIMAL,
+        lineterminator="\r\n",
+    )
+    writer.writeheader()
+    for c in cards:
+        writer.writerow({
+            "term": c.get("term") or "",
+            "translation": c.get("translation") or "",
+            "context": c.get("context_sentence") or c.get("context") or "",
+            "phonetic": c.get("phonetic") or "",
+            "part_of_speech": c.get("part_of_speech") or "",
+            "definition_en": c.get("definition_en") or "",
+            "collection": c.get("collection") or "General",
+            "tags": c.get("tags") or "",
+            "notes": c.get("notes") or "",
+            "created_at": c.get("created_at") or "",
+        })
+    # UTF-8 BOM (\ufeff) so Excel auto-detects encoding
+    return ("\ufeff" + output.getvalue()).encode("utf-8")
+
+
+def export_json(cards: List[Dict[str, Any]]) -> bytes:
+    """Full JSON export with metadata header."""
+    payload = {
+        "exported_at": datetime.now(timezone.utc).isoformat(),
+        "total": len(cards),
+        "cards": [
+            {
+                "id": c.get("id"),
+                "term": c.get("term") or "",
+                "translation": c.get("translation") or "",
+                "context_sentence": c.get("context_sentence") or c.get("context") or "",
+                "phonetic": c.get("phonetic") or "",
+                "part_of_speech": c.get("part_of_speech") or "",
+                "definition_en": c.get("definition_en") or "",
+                "collection": c.get("collection") or "General",
+                "tags": c.get("tags") or "",
+                "notes": c.get("notes") or "",
+                "audio_url": c.get("audio_url") or "",
+                "created_at": c.get("created_at") or "",
+                "updated_at": c.get("updated_at") or "",
+            }
+            for c in cards
+        ],
+    }
+    return json.dumps(payload, ensure_ascii=False, indent=2).encode("utf-8")
+
+
+def export_anki_tsv(cards: List[Dict[str, Any]]) -> bytes:
+    """
+    Anki-compatible tab-separated export with cloze deletion support.
+    """
+    lines: List[str] = [
+        "#separator:tab",
+        "#html:true",
+        "#notetype:Basic (and reversed card)",
+        "#columns:Front\tBack\tTags\tContext",
+    ]
+    for c in cards:
+        term = (c.get("term") or "").replace("\t", " ").replace("\n", " ")
+        translation = (c.get("translation") or "").replace("\t", " ").replace("\n", " ")
+        phonetic = (c.get("phonetic") or "").replace("\t", " ")
+        context = (c.get("context_sentence") or c.get("context") or "").replace("\t", " ").replace("\n", " ")
+        tags_raw = c.get("tags") or ""
+        collection = (c.get("collection") or "General").strip().replace(" ", "_")
+
+        # Cloze representation if context contains the term
+        cloze_ctx = ""
+        if context and term and term.lower() in context.lower():
+            cloze_ctx = re.sub(re.escape(term), f"{{{{c1::{term}}}}}", context, flags=re.IGNORECASE)
+
+        tag_parts = [f"collection_{collection}"] + [
+            t.strip().replace(" ", "_")
+            for t in tags_raw.split(",") if t.strip()
+        ]
+        tags_str = " ".join(tag_parts)
+
+        front = term if not phonetic else f"{term}  [{phonetic}]"
+        back = translation
+
+        lines.append(f"{front}\t{back}\t{tags_str}\t{cloze_ctx or context}")
+
+    return ("\n".join(lines) + "\n").encode("utf-8")
+
+
+def export_markdown(cards: List[Dict[str, Any]]) -> bytes:
+    """Human-readable Markdown export, grouped by collection."""
+    now_str = datetime.now(timezone.utc).strftime("%Y-%m-%d %H:%M UTC")
+    lines: List[str] = [
+        f"# 📚 Vocabulary Export — {now_str}",
+        f"**Total cards:** {len(cards)}",
+        "",
+    ]
+
+    by_collection: Dict[str, List[Dict[str, Any]]] = {}
+    for c in cards:
+        col = (c.get("collection") or "General").strip()
+        by_collection.setdefault(col, []).append(c)
+
+    for collection, col_cards in sorted(by_collection.items()):
+        lines.append(f"## {collection} ({len(col_cards)} cards)")
+        lines.append("")
+        lines.append("| Term | Translation | Phonetic | Tags |")
+        lines.append("|------|-------------|----------|------|")
+        for c in col_cards:
+            term = (c.get("term") or "").replace("|", "\\|")
+            translation = (c.get("translation") or "").replace("|", "\\|")
+            phonetic = (c.get("phonetic") or "").replace("|", "\\|")
+            tags = (c.get("tags") or "").replace("|", "\\|")
+            lines.append(f"| **{term}** | {translation} | {phonetic} | {tags} |")
+        lines.append("")
+        lines.append("### Details")
+        lines.append("")
+        for c in col_cards:
+            term = c.get("term") or ""
+            phonetic_str = f" `{c['phonetic']}`" if c.get("phonetic") else ""
+            pos_str = f" *({c['part_of_speech']})*" if c.get("part_of_speech") else ""
+            lines.append(f"### {term}{phonetic_str}{pos_str}")
+            lines.append(f"- **Перевод**: {c.get('translation') or '—'}")
+            if c.get("definition_en"):
+                lines.append(f"- **Толкование**: {c['definition_en']}")
+            if c.get("context_sentence") or c.get("context"):
+                lines.append(f"- **Контекст**: *\"{c.get('context_sentence') or c.get('context')}\"*")
+            if c.get("notes"):
+                lines.append(f"- **Заметка**: {c['notes']}")
+            lines.append("")
+
+    return ("\n".join(lines) + "\n").encode("utf-8")

app/srs.py

@@ -0,0 +1,250 @@
+"""
+SuperMemo-2 (SM-2) spaced repetition system (SRS) calculation logic,
+quiz generation, and activity heatmap / streak analysis.
+"""
+from datetime import datetime, timedelta, timezone, date
+from typing import Dict, Any, Optional, List
+import random
+
+# Quality rating constants
+RATING_AGAIN = 1
+RATING_HARD = 2
+RATING_GOOD = 3
+RATING_EASY = 4
+
+MIN_EASE = 1.3
+MAX_EASE = 3.0
+DEFAULT_EASE = 2.5
+MASTERED_INTERVAL_THRESHOLD = 21
+
+FALLBACK_DISTRACTORS = [
+    ("concurrency", "одновременность, параллелизм"),
+    ("throughput", "пропускная способность"),
+    ("bottleneck", "узкое место"),
+    ("redundancy", "избыточность, резервирование"),
+    ("resilience", "устойчивость, отказоустойчивость"),
+    ("deprecated", "устаревший, не рекомендуемый"),
+    ("mitigate", "смягчать, уменьшать последствия"),
+    ("seamless", "бесшовный, плавный"),
+    ("leverage", "использовать с выгодой"),
+    ("tweak", "подправить, тонко настроить"),
+    ("scaffold", "каркас, шаблон структуры"),
+    ("boilerplate", "шаблонный код"),
+    ("payload", "полезная нагрузка"),
+    ("latency", "задержка, пинг"),
+    ("invoke", "вызывать (функцию/метод)"),
+    ("retrieve", "извлекать, получать данные"),
+    ("subtle", "тонкий, едва уловимый"),
+    ("comprehensive", "всесторонний, исчерпывающий"),
+    ("reluctant", "неохотный, нежелающий"),
+    ("perseverance", "настойчивость, упорство"),
+    ("serendipity", "счастливая случайность"),
+    ("ubiquitous", "вездесущий, повсеместный"),
+    ("indispensable", "незаменимый"),
+    ("arbitrary", "произвольный"),
+    ("coherent", "связный, последовательный"),
+    ("feasible", "осуществимый, выполнимый"),
+    ("tangible", "осязаемый, ощутимый"),
+    ("robust", "надежный, устойчивый к сбоям"),
+    ("versatile", "универсальный, гибкий"),
+    ("streamline", "оптимизировать, упрощать"),
+]
+
+
+def calculate_next_review(interval_days: int, base_time: Optional[datetime] = None) -> str:
+    """Calculates the next review timestamp formatted as 'YYYY-MM-DD HH:MM:SS' (UTC)."""
+    if base_time is None:
+        base_time = datetime.now(timezone.utc)
+    next_time = base_time + timedelta(days=interval_days)
+    return next_time.strftime("%Y-%m-%d %H:%M:%S")
+
+
+def calculate_sm2(
+    rating: int,
+    reps: Optional[int] = 0,
+    interval: Optional[int] = 0,
+    ease: Optional[float] = 2.5,
+    state: Optional[str] = "new",
+    base_time: Optional[datetime] = None,
+    error_count: Optional[int] = 0,
+) -> Dict[str, Any]:
+    """
+    Processes a card review rating using SM-2 algorithm:
+      - 1: Again (reps=0, interval=1, ease = max(1.3, ease - 0.2), state='learning')
+      - 2: Hard (reps=reps+1, interval=max(1, round(interval * 1.2)), ease = max(1.3, ease - 0.15), state='learning' if reps < 3 else 'review')
+      - 3: Good (reps=reps+1, interval= 1 if reps==1 else (6 if reps==2 else round(interval * ease)), state='review' if interval < 21 else 'mastered')
+      - 4: Easy (reps=reps+1, interval= 4 if reps==1 else round(interval * ease * 1.3), ease = min(3.0, ease + 0.15), state='review' if interval < 21 else 'mastered')
+    """
+    if rating not in (RATING_AGAIN, RATING_HARD, RATING_GOOD, RATING_EASY):
+        raise ValueError(f"Invalid rating {rating}: must be 1 (Again), 2 (Hard), 3 (Good), or 4 (Easy)")
+
+    reps = reps if reps is not None else 0
+    interval = interval if interval is not None else 0
+    ease = ease if ease is not None else DEFAULT_EASE
+    state = state or "new"
+    error_count = error_count if error_count is not None else 0
+
+    if base_time is None:
+        base_time = datetime.now(timezone.utc)
+    last_review_str = base_time.strftime("%Y-%m-%d %H:%M:%S")
+
+    new_error_count = error_count
+    if rating == RATING_AGAIN:
+        new_reps = 0
+        new_interval = 1
+        new_ease = max(MIN_EASE, ease - 0.2)
+        new_state = "learning"
+        new_error_count += 1
+
+    elif rating == RATING_HARD:
+        new_reps = reps + 1
+        new_interval = max(1, round(interval * 1.2))
+        new_ease = max(MIN_EASE, ease - 0.15)
+        new_state = "learning" if new_reps < 3 else "review"
+
+    elif rating == RATING_GOOD:
+        new_reps = reps + 1
+        if new_reps == 1:
+            new_interval = 1
+        elif new_reps == 2:
+            new_interval = 6
+        else:
+            new_interval = round(interval * ease)
+        new_ease = ease
+        new_state = "review" if new_interval < MASTERED_INTERVAL_THRESHOLD else "mastered"
+
+    elif rating == RATING_EASY:
+        new_reps = reps + 1
+        if new_reps == 1:
+            new_interval = 4
+        else:
+            new_interval = round(interval * ease * 1.3)
+        new_ease = min(MAX_EASE, ease + 0.15)
+        new_state = "review" if new_interval < MASTERED_INTERVAL_THRESHOLD else "mastered"
+
+    new_ease = round(new_ease, 2)
+    next_review_str = calculate_next_review(new_interval, base_time)
+
+    return {
+        "srs_reps": new_reps,
+        "srs_interval": new_interval,
+        "srs_ease": new_ease,
+        "srs_state": new_state,
+        "srs_last_review": last_review_str,
+        "srs_next_review": next_review_str,
+        "error_count": new_error_count,
+    }
+
+
+def generate_quiz_options(target_card: Dict[str, Any], all_cards: List[Dict[str, Any]], count: int = 4) -> List[Dict[str, Any]]:
+    """
+    Generates 4 multiple choice options for a target card (1 correct + 3 distractors).
+    Returns list of options with text and is_correct flag, randomly shuffled.
+    """
+    target_id = target_card.get("id")
+    correct_text = target_card.get("translation", "")
+
+    # Gather potential distractors from user's other cards
+    candidate_distractors = [
+        c.get("translation", "").strip()
+        for c in all_cards
+        if c.get("id") != target_id and c.get("translation", "").strip() and c.get("translation", "").strip() != correct_text
+    ]
+
+    # Deduplicate candidates
+    candidate_distractors = list(dict.fromkeys(candidate_distractors))
+    random.shuffle(candidate_distractors)
+
+    selected_distractors: List[str] = []
+    for d in candidate_distractors:
+        if len(selected_distractors) >= (count - 1):
+            break
+        selected_distractors.append(d)
+
+    # If still not enough, take from fallback dictionary
+    if len(selected_distractors) < (count - 1):
+        for _, ru in FALLBACK_DISTRACTORS:
+            if ru != correct_text and ru not in selected_distractors:
+                selected_distractors.append(ru)
+            if len(selected_distractors) >= (count - 1):
+                break
+
+    options = [{"text": correct_text, "is_correct": True}]
+    for d in selected_distractors:
+        options.append({"text": d, "is_correct": False})
+
+    random.shuffle(options)
+    return options
+
+
+def build_activity_heatmap(review_dates: Dict[str, int], days: int = 180) -> Dict[str, Any]:
+    """
+    Constructs a daily contribution heatmap (like GitHub) for the past `days`.
+    Returns daily entries with date, count, and level (0: none, 1: 1 review, 2: 2-3 reviews, 3: 4+ reviews).
+    Also computes current streak and longest streak.
+    """
+    today = date.today()
+    start_date = today - timedelta(days=days - 1)
+
+    heatmap_days = []
+    current_date = start_date
+
+    while current_date <= today:
+        d_str = current_date.strftime("%Y-%m-%d")
+        count = review_dates.get(d_str, 0)
+        if count == 0:
+            level = 0
+        elif count == 1:
+            level = 1
+        elif count <= 3:
+            level = 2
+        else:
+            level = 3
+
+        heatmap_days.append({
+            "date": d_str,
+            "count": count,
+            "level": level,
+            "day_of_week": current_date.weekday(),  # 0=Mon, 6=Sun
+        })
+        current_date += timedelta(days=1)
+
+    # Compute streaks
+    current_streak = 0
+    check_day = today
+    # Check today
+    if review_dates.get(check_day.strftime("%Y-%m-%d"), 0) > 0:
+        current_streak += 1
+        check_day -= timedelta(days=1)
+    else:
+        # If no activity today yet, check yesterday to preserve ongoing streak
+        yesterday = today - timedelta(days=1)
+        if review_dates.get(yesterday.strftime("%Y-%m-%d"), 0) > 0:
+            check_day = yesterday
+
+    while check_day >= start_date:
+        if review_dates.get(check_day.strftime("%Y-%m-%d"), 0) > 0:
+            if check_day != today:  # don't double-count today
+                current_streak += 1
+            check_day -= timedelta(days=1)
+        else:
+            break
+
+    # Longest streak calculation
+    longest_streak = 0
+    temp_streak = 0
+    for day in heatmap_days:
+        if day["count"] > 0:
+            temp_streak += 1
+            if temp_streak > longest_streak:
+                longest_streak = temp_streak
+        else:
+            temp_streak = 0
+
+    return {
+        "days": heatmap_days,
+        "total_active_days": sum(1 for d in heatmap_days if d["count"] > 0),
+        "total_reviews": sum(d["count"] for d in heatmap_days),
+        "current_streak": current_streak,
+        "longest_streak": max(longest_streak, current_streak),
+    }

app/static/css/style.css

@@ -1905,6 +1905,382 @@ body {
     justify-content: center;
 }
 
+/* Duplicate Warning Banner */
+.duplicate-warning-box {
+    margin-top: 10px;
+    padding: 10px 14px;
+    background: rgba(234, 179, 8, 0.12);
+    border: 1px solid rgba(234, 179, 8, 0.35);
+    border-radius: var(--radius-md);
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    gap: 12px;
+    animation: fadeIn 0.2s ease-in-out;
+}
+
+.dup-left {
+    display: flex;
+    align-items: center;
+    gap: 8px;
+    font-size: 13px;
+    color: #facc15;
+}
+
+.dup-icon {
+    font-size: 16px;
+}
+
+/* Multiple Choice Quiz Mode */
+.quiz-card {
+    max-width: 680px;
+    margin: 0 auto;
+}
+
+.quiz-hero {
+    text-align: center;
+    padding: 20px 0 16px 0;
+    border-bottom: 1px solid var(--border-color);
+    margin-bottom: 20px;
+}
+
+.quiz-prompt-row {
+    display: flex;
+    align-items: center;
+    justify-content: center;
+    gap: 12px;
+}
+
+.quiz-term-display {
+    font-size: 32px;
+    font-weight: 800;
+    color: var(--text-main);
+    letter-spacing: -0.02em;
+}
+
+.quiz-context-hint {
+    margin-top: 8px;
+    font-size: 14px;
+    color: var(--text-muted);
+    font-style: italic;
+}
+
+.quiz-options-grid {
+    display: grid;
+    grid-template-columns: 1fr 1fr;
+    gap: 14px;
+    margin-bottom: 16px;
+}
+
+.quiz-option-btn {
+    display: flex;
+    align-items: center;
+    gap: 12px;
+    padding: 16px 18px;
+    background: var(--bg-main);
+    border: 2px solid var(--border-color);
+    border-radius: var(--radius-md);
+    color: var(--text-main);
+    font-size: 15px;
+    font-weight: 600;
+    text-align: left;
+    cursor: pointer;
+    transition: all 0.15s ease;
+    user-select: none;
+}
+
+.quiz-option-btn:hover:not(:disabled) {
+    border-color: var(--primary);
+    background: var(--bg-surface-hover);
+    transform: translateY(-1px);
+}
+
+.quiz-option-btn:disabled {
+    cursor: default;
+}
+
+.quiz-opt-num {
+    width: 26px;
+    height: 26px;
+    border-radius: 50%;
+    background: var(--bg-surface);
+    border: 1px solid var(--border-color);
+    display: inline-flex;
+    align-items: center;
+    justify-content: center;
+    font-size: 12px;
+    font-weight: 700;
+    color: var(--text-muted);
+    flex-shrink: 0;
+}
+
+.quiz-opt-text {
+    flex: 1;
+    line-height: 1.35;
+}
+
+.quiz-option-btn.opt-correct {
+    background: rgba(34, 197, 94, 0.15) !important;
+    border-color: var(--success) !important;
+    color: var(--success) !important;
+}
+
+.quiz-option-btn.opt-correct .quiz-opt-num {
+    background: var(--success);
+    color: #ffffff;
+    border-color: var(--success);
+}
+
+.quiz-option-btn.opt-wrong {
+    background: rgba(239, 68, 68, 0.15) !important;
+    border-color: var(--danger) !important;
+    color: var(--danger) !important;
+    animation: shake 0.3s ease;
+}
+
+.quiz-option-btn.opt-wrong .quiz-opt-num {
+    background: var(--danger);
+    color: #ffffff;
+    border-color: var(--danger);
+}
+
+.quiz-next-bar {
+    margin-top: 16px;
+}
+
+/* Active Typing Mode */
+.typing-hero {
+    text-align: center;
+    padding: 16px 0 20px 0;
+}
+
+.typing-prompt-ru {
+    font-size: 28px;
+    font-weight: 800;
+    color: var(--primary);
+    margin: 8px 0;
+}
+
+.typing-context-hint {
+    font-size: 14px;
+    color: var(--text-muted);
+    font-style: italic;
+    background: var(--bg-main);
+    padding: 8px 12px;
+    border-radius: var(--radius-sm);
+    display: inline-block;
+    max-width: 90%;
+    margin-top: 4px;
+}
+
+/* Analytics & Activity Heatmap Modal */
+.stats-modal-window {
+    max-width: 820px;
+    width: 95%;
+}
+
+.stats-hero-grid {
+    display: grid;
+    grid-template-columns: repeat(4, 1fr);
+    gap: 12px;
+    margin-bottom: 24px;
+}
+
+.stat-kpi-card {
+    background: var(--bg-main);
+    border: 1px solid var(--border-color);
+    border-radius: var(--radius-md);
+    padding: 14px 12px;
+    text-align: center;
+    display: flex;
+    flex-direction: column;
+    align-items: center;
+    gap: 4px;
+}
+
+.streak-kpi {
+    border-color: rgba(249, 115, 22, 0.4);
+    background: rgba(249, 115, 22, 0.05);
+}
+
+.kpi-icon {
+    font-size: 24px;
+}
+
+.kpi-value {
+    font-size: 26px;
+    font-weight: 800;
+    line-height: 1.1;
+}
+
+.kpi-label {
+    font-size: 12px;
+    font-weight: 600;
+    color: var(--text-muted);
+}
+
+.kpi-sub {
+    font-size: 11px;
+    color: var(--text-dim);
+}
+
+.text-accent {
+    color: #38bdf8;
+}
+
+/* GitHub Heatmap Section */
+.heatmap-section {
+    background: var(--bg-main);
+    border: 1px solid var(--border-color);
+    border-radius: var(--radius-md);
+    padding: 16px;
+    margin-bottom: 20px;
+}
+
+.heatmap-header {
+    display: flex;
+    align-items: center;
+    justify-content: space-between;
+    margin-bottom: 14px;
+    flex-wrap: wrap;
+    gap: 8px;
+}
+
+.heatmap-header h4 {
+    font-size: 15px;
+    font-weight: 700;
+}
+
+.heatmap-legend {
+    display: flex;
+    align-items: center;
+    gap: 5px;
+    font-size: 11px;
+    color: var(--text-dim);
+}
+
+.legend-cell {
+    width: 12px;
+    height: 12px;
+    border-radius: 2px;
+    display: inline-block;
+}
+
+.heatmap-container-wrap {
+    overflow-x: auto;
+    padding-bottom: 6px;
+}
+
+.heatmap-grid {
+    display: grid;
+    grid-auto-flow: column;
+    grid-template-rows: repeat(7, 12px);
+    gap: 4px;
+    min-width: 600px;
+}
+
+.heatmap-cell {
+    width: 12px;
+    height: 12px;
+    border-radius: 2px;
+    background: rgba(255, 255, 255, 0.05);
+    cursor: pointer;
+    transition: transform 0.1s ease;
+    position: relative;
+}
+
+.heatmap-cell:hover {
+    transform: scale(1.3);
+    z-index: 10;
+    outline: 1px solid var(--text-main);
+}
+
+/* Heatmap Levels (GitHub-style intensity) */
+.lvl-0 { background: rgba(255, 255, 255, 0.06); }
+.lvl-1 { background: #166534; }  /* 1 review: soft green */
+.lvl-2 { background: #22c55e; }  /* 2-3 reviews: vibrant green */
+.lvl-3 { background: #4ade80; }  /* 4+ reviews: bright intense green */
+
+[data-theme="light"] .lvl-0 { background: #e2e8f0; }
+[data-theme="light"] .lvl-1 { background: #86efac; }
+[data-theme="light"] .lvl-2 { background: #22c55e; }
+[data-theme="light"] .lvl-3 { background: #15803d; }
+
+.heatmap-footer-note {
+    margin-top: 10px;
+    color: var(--text-dim);
+    font-size: 11px;
+}
+
+/* Segmented Mastery Progress Bar */
+.mastery-section {
+    background: var(--bg-main);
+    border: 1px solid var(--border-color);
+    border-radius: var(--radius-md);
+    padding: 16px;
+}
+
+.mastery-section h4 {
+    font-size: 15px;
+    font-weight: 700;
+    margin-bottom: 12px;
+}
+
+.segmented-progress-bar {
+    display: flex;
+    height: 14px;
+    background: var(--bg-surface);
+    border-radius: var(--radius-full);
+    overflow: hidden;
+    margin-bottom: 12px;
+    border: 1px solid var(--border-color);
+}
+
+.prog-segment {
+    height: 100%;
+    transition: width 0.3s ease;
+}
+
+.seg-mastered { background: #22c55e; }
+.seg-review   { background: #38bdf8; }
+.seg-learning { background: #f59e0b; }
+.seg-new      { background: #64748b; }
+
+.mastery-legend-row {
+    display: flex;
+    gap: 16px;
+    flex-wrap: wrap;
+    font-size: 12px;
+}
+
+.m-legend-item {
+    display: flex;
+    align-items: center;
+    gap: 6px;
+    color: var(--text-muted);
+}
+
+.dot {
+    width: 8px;
+    height: 8px;
+    border-radius: 50%;
+    display: inline-block;
+}
+
+.dot-mastered { background: #22c55e; }
+.dot-review   { background: #38bdf8; }
+.dot-learning { background: #f59e0b; }
+.dot-new      { background: #64748b; }
+.dot-leech    { background: #ef4444; }
+
+.text-danger  { color: #ef4444; }
+
+@keyframes shake {
+    0%, 100% { transform: translateX(0); }
+    25% { transform: translateX(-4px); }
+    75% { transform: translateX(4px); }
+}
+
 /* Responsive */
 @media (max-width: 640px) {
     .navbar {
@@ -1939,12 +2315,14 @@ body {
         min-width: 0;
         width: 100%;
     }
+    .fc-flip-btn-wrap {
         display: block;
     }
     .srs-topbar {
         padding: 10px 12px;
         flex-direction: column;
         align-items: stretch;
+        gap: 8px;
     }
     .srs-topbar-left, .srs-topbar-right {
         justify-content: space-between;
@@ -1955,6 +2333,12 @@ body {
     .srs-rating-bar {
         grid-template-columns: 1fr 1fr;
     }
+    .quiz-options-grid {
+        grid-template-columns: 1fr;
+    }
+    .stats-hero-grid {
+        grid-template-columns: 1fr 1fr;
+    }
     .export-grid {
         grid-template-columns: 1fr;
     }
@@ -1972,3 +2356,4 @@ body {
     }
 }
 
+

app/static/icons/icon.svg

@@ -0,0 +1,73 @@
+<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 512 512" width="512" height="512">
+  <defs>
+    <linearGradient id="bgGrad" x1="0%" y1="0%" x2="100%" y2="100%">
+      <stop offset="0%" stop-color="#0f172a"/>
+      <stop offset="50%" stop-color="#1e293b"/>
+      <stop offset="100%" stop-color="#090d16"/>
+    </linearGradient>
+    <linearGradient id="accentGrad" x1="0%" y1="0%" x2="100%" y2="100%">
+      <stop offset="0%" stop-color="#38bdf8"/>
+      <stop offset="100%" stop-color="#0284c7"/>
+    </linearGradient>
+    <linearGradient id="emeraldGrad" x1="0%" y1="0%" x2="100%" y2="100%">
+      <stop offset="0%" stop-color="#34d399"/>
+      <stop offset="100%" stop-color="#059669"/>
+    </linearGradient>
+    <filter id="glow" x="-20%" y="-20%" width="140%" height="140%">
+      <feGaussianBlur stdDeviation="16" result="blur" />
+      <feComposite in="SourceGraphic" in2="blur" operator="over" />
+    </filter>
+  </defs>
+
+  <!-- Base Rounded Container -->
+  <rect width="512" height="512" rx="115" fill="url(#bgGrad)"/>
+  <rect width="510" height="510" x="1" y="1" rx="114" fill="none" stroke="#334155" stroke-width="2"/>
+  <rect width="500" height="500" x="6" y="6" rx="110" fill="none" stroke="url(#accentGrad)" stroke-width="3" stroke-opacity="0.4"/>
+
+  <!-- Glowing Accent Light -->
+  <circle cx="256" cy="180" r="140" fill="#38bdf8" opacity="0.12" filter="url(#glow)"/>
+
+  <!-- Open Book Symbol -->
+  <g transform="translate(96, 150)">
+    <!-- Book Left Page -->
+    <path d="M152 40 C110 20, 45 22, 10 32 C4 34, 0 39, 0 46 L0 236 C0 244, 7 250, 15 248 C48 240, 110 238, 152 258 Z" 
+          fill="#1e293b" stroke="#38bdf8" stroke-width="8" stroke-linejoin="round"/>
+    
+    <!-- Book Right Page -->
+    <path d="M168 40 C210 20, 275 22, 310 32 C316 34, 320 39, 320 46 L320 236 C320 244, 313 250, 305 248 C272 240, 210 238, 168 258 Z" 
+          fill="#1e293b" stroke="#38bdf8" stroke-width="8" stroke-linejoin="round"/>
+
+    <!-- Spine -->
+    <path d="M160 36 L160 262" stroke="#38bdf8" stroke-width="10" stroke-linecap="round"/>
+
+    <!-- Left Page Text Lines -->
+    <line x1="36" y1="84" x2="124" y2="76" stroke="#94a3b8" stroke-width="7" stroke-linecap="round" opacity="0.8"/>
+    <line x1="36" y1="124" x2="124" y2="116" stroke="#94a3b8" stroke-width="7" stroke-linecap="round" opacity="0.8"/>
+    <line x1="36" y1="164" x2="104" y2="156" stroke="#94a3b8" stroke-width="7" stroke-linecap="round" opacity="0.8"/>
+
+    <!-- Right Page Text Lines -->
+    <line x1="196" y1="76" x2="284" y2="84" stroke="#94a3b8" stroke-width="7" stroke-linecap="round" opacity="0.8"/>
+    <line x1="196" y1="116" x2="284" y2="124" stroke="#94a3b8" stroke-width="7" stroke-linecap="round" opacity="0.8"/>
+    <line x1="196" y1="156" x2="254" y2="164" stroke="#94a3b8" stroke-width="7" stroke-linecap="round" opacity="0.8"/>
+
+    <!-- Bookmark Ribbon -->
+    <path d="M152 26 L152 140 L160 128 L168 140 L168 26 Z" fill="url(#emeraldGrad)"/>
+  </g>
+
+  <!-- SRS / Spaced Repetition Learning Sparkle / Cap atop -->
+  <g transform="translate(256, 120)">
+    <circle cx="0" cy="0" r="14" fill="#38bdf8"/>
+    <path d="M-8 0 L8 0 M0 -8 L0 8" stroke="#ffffff" stroke-width="3" stroke-linecap="round"/>
+    <circle cx="-38" cy="12" r="6" fill="#34d399"/>
+    <circle cx="38" cy="12" r="6" fill="#34d399"/>
+  </g>
+
+  <!-- Bottom Accent Text "NOTES" -->
+  <text x="256" y="446" 
+        font-family="system-ui, -apple-system, sans-serif" 
+        font-size="34" 
+        font-weight="900" 
+        letter-spacing="6" 
+        fill="#f8fafc" 
+        text-anchor="middle">NOTES</text>
+</svg>

app/static/index.html

@@ -1,65 +1,93 @@
 <!DOCTYPE html>
-<html lang="ru">
+<html lang="ru" data-theme="dark">
 <head>
     <meta charset="UTF-8">
-    <meta name="viewport" content="width=device-width, initial-scale=1.0">
-    <title>Notes — Персональный тренажёр английского языка</title>
+    <meta name="viewport" content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=no">
+    <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">
-    <link rel="icon" href="data:image/svg+xml,<svg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 100 100'><text y='.9em' font-size='90'>📖</text></svg>">
+    
+    <!-- PWA meta and icons -->
+    <link rel="manifest" href="/manifest.json">
+    <meta name="theme-color" content="#0f172a">
+    <meta name="apple-mobile-web-app-capable" content="yes">
+    <meta name="apple-mobile-web-app-status-bar-style" content="black-translucent">
+    <meta name="apple-mobile-web-app-title" content="Notes English">
+    <link rel="apple-touch-icon" href="/static/icons/icon-192.png">
 </head>
 <body>
-
-    <!-- Login Modal / Screen -->
-    <div id="auth-screen" class="auth-screen hidden">
-        <div class="auth-card">
-            <div class="auth-header">
-                <div class="app-logo">📖</div>
-                <h2>Вход в Notes</h2>
-                <p>Персональный словарь и тренажёр языка</p>
+    <!-- Login Overlay / Page -->
+    <div id="login-overlay" class="login-overlay hidden">
+        <div class="login-card">
+            <div class="login-header">
+                <div class="login-logo">📖</div>
+                <h1>Notes</h1>
+                <p>Персональный словарь и тренажёр английского языка</p>
             </div>
-            <form id="login-form">
+
+            <form id="login-form" class="login-form">
                 <div class="form-group">
-                    <label for="username">Имя пользователя</label>
-                    <input type="text" id="username" autocomplete="username" required placeholder="admin" autofocus>
+                    <label for="login-username">Имя пользователя</label>
+                    <input type="text" id="login-username" class="input-styled" autocomplete="username" required autofocus placeholder="admin">
                 </div>
+
                 <div class="form-group">
-                    <label for="password">Пароль</label>
-                    <input type="password" id="password" autocomplete="current-password" required placeholder="••••••••">
+                    <label for="login-password">Пароль</label>
+                    <input type="password" id="login-password" class="input-styled" autocomplete="current-password" required placeholder="••••••••">
                 </div>
-                <div id="auth-error" class="error-banner hidden"></div>
-                <button type="submit" id="login-btn" class="btn btn-primary btn-block">Войти в систему</button>
+
+                <div id="login-error" class="login-error hidden"></div>
+
+                <button type="submit" id="login-submit-btn" class="btn btn-primary btn-block">
+                    Войти в словарь
+                </button>
             </form>
-            <div class="auth-footer">
-                <span>Защищённый контур: notes.qpid.pro</span>
+            <div class="login-footer">
+                <small>Безопасное хранилище словаря • notes.qpid.pro</small>
             </div>
         </div>
     </div>
 
-    <!-- Main Application UI -->
-    <div id="app-container" class="app-container hidden">
-        <!-- Top Navigation -->
+    <!-- Main Application Shell -->
+    <div id="app-shell" class="app-shell">
+        <!-- Top Navigation Bar -->
         <header class="navbar">
-            <div class="nav-brand">
+            <div class="nav-brand" id="nav-brand-home" title="На главную">
                 <span class="brand-icon">📖</span>
                 <span class="brand-title">Notes</span>
                 <span class="brand-sub">English Lexicon</span>
             </div>
 
-            <div class="nav-stats" id="nav-stats">
-                <span class="stat-badge" title="Всего слов в словаре">Всего: <strong id="stat-total">0</strong></span>
-                <span class="stat-badge stat-today" title="Добавлено сегодня">Сегодня: <strong id="stat-today">+0</strong></span>
+            <div class="nav-center">
+                <div class="nav-stats" id="nav-stats">
+                    <span class="stat-badge" title="Всего слов в словаре">Всего: <strong id="stat-total">0</strong></span>
+                    <span class="stat-badge stat-today" title="Добавлено сегодня">Сегодня: <strong id="stat-today">+0</strong></span>
+                </div>
             </div>
 
             <div class="nav-actions">
+                <button id="srs-trainer-btn" class="btn btn-trainer" title="Интервальный тренажер (Flashcards, 4 варианта, диктант, ввод)">
+                    <span class="trainer-icon">🎓</span>
+                    <span class="trainer-text">Тренажёр SRS</span>
+                    <span id="srs-badge" class="srs-due-badge">0</span>
+                </button>
+                <button id="stats-open-btn" class="btn btn-outline btn-sm stat-open-btn" title="Активность (GitHub Heatmap) и аналитика">
+                    <span>📊 Статистика</span>
+                </button>
+                <button id="export-open-btn" class="btn btn-outline btn-sm" title="Экспорт словаря">
+                    <span>📤 Экспорт</span>
+                </button>
                 <button id="theme-toggle" class="icon-btn" title="Переключить тему">🌓</button>
                 <div class="user-profile">
                     <span id="user-display-name" class="user-badge">user</span>
+                    <button id="change-pwd-open-btn" class="btn btn-sm btn-outline" title="Сменить пароль">🔑 Пароль</button>
                     <button id="logout-btn" class="btn btn-sm btn-outline" title="Выйти из аккаунта">Выход</button>
                 </div>
             </div>
         </header>
 
-        <main class="main-content">
+        <!-- VIEW 1: Main Dictionary & Capture View -->
+        <main class="main-content" id="dictionary-view">
             <!-- Search & Translation Section -->
             <section class="search-section">
                 <div class="search-box-wrapper">
@@ -70,6 +98,15 @@
                         <button id="translate-btn" class="btn btn-primary translate-action-btn">Перевести</button>
                     </div>
 
+                    <!-- Duplicate Warning Notification -->
+                    <div id="duplicate-warning-box" class="duplicate-warning-box hidden">
+                        <div class="dup-left">
+                            <span class="dup-icon">⚠️</span>
+                            <span class="dup-text">Это слово уже есть в вашем словаре: <strong id="dup-term-label"></strong> (<em id="dup-trans-label"></em>)</span>
+                        </div>
+                        <button id="dup-open-btn" class="btn btn-xs btn-outline">Посмотреть / Дополнить</button>
+                    </div>
+
                     <div class="hotkey-hints">
                         <span class="hint-item"><kbd>Enter</kbd> перевод</span>
                         <span class="hint-item"><kbd>Ctrl</kbd>+<kbd>Enter</kbd> сохранить</span>
@@ -78,58 +115,51 @@
                     </div>
                 </div>
 
-                <!-- Loader -->
-                <div id="lookup-spinner" class="lookup-spinner hidden">
-                    <div class="spinner"></div>
-                    <span>Ищем толкование, произношение и перевод...</span>
-                </div>
+                <!-- Live Translation & Dictionary Lookup Result Card -->
+                <div id="lookup-card" class="lookup-card hidden">
+                    <div class="lookup-header">
+                        <div class="lookup-term-group">
+                            <h2 id="res-term" class="res-term">Word</h2>
+                            <span id="res-phonetic" class="res-phonetic">/wɜːd/</span>
+                            <button id="audio-play-btn" class="icon-btn audio-btn hidden" title="Прослушать произношение">🔊</button>
+                        </div>
+                        <span id="res-pos" class="badge-pos">Noun</span>
+                    </div>
 
-                <!-- Live Result Card -->
-                <div id="result-card" class="result-card hidden">
-                    <div class="result-header">
-                        <div class="term-title-row">
-                            <h2 id="res-term" class="res-term">reluctant</h2>
-                            <span id="res-phonetic" class="res-phonetic badge-pill">/rɪˈlʌktənt/</span>
-                            <span id="res-pos" class="res-pos badge-pill">Adjective</span>
-                            <button id="play-audio-btn" class="audio-btn" title="Прослушать произношение">
-                                🔊 <span class="audio-text">Слушать</span>
-                            </button>
+                    <!-- English Definition if available -->
+                    <div id="res-definition-wrap" class="definition-wrap hidden">
+                        <div class="def-label">Толкование (EN):</div>
+                        <div id="res-definition" class="res-definition"></div>
+                    </div>
+
+                    <!-- Primary Translation Field (Editable before saving) -->
+                    <div class="form-group edit-translation-group">
+                        <label for="edit-translation">Перевод на русский язык:</label>
+                        <div class="input-with-button">
+                            <input type="text" id="edit-translation" class="input-styled" placeholder="Русский перевод...">
                         </div>
                     </div>
 
-                    <div id="res-definition-box" class="definition-box">
-                        <div class="def-label">Толкование (English):</div>
-                        <p id="res-definition" class="def-text"></p>
+                    <!-- Context & Extra Details Box -->
+                    <div class="context-group">
+                        <label for="edit-context">Контекстное предложение (где встретилось выражение):</label>
+                        <textarea id="edit-context" class="input-styled textarea-context" rows="2" placeholder="He was reluctant to admit his mistake during the team retrospective..."></textarea>
                     </div>
 
-                    <div class="card-edit-grid">
-                        <div class="field-group">
-                            <label for="edit-translation">Перевод на русский <span class="req">*</span></label>
-                            <input type="text" id="edit-translation" class="input-styled" placeholder="Основной перевод...">
-                            <div id="translation-suggestions" class="suggestions-chips"></div>
-                        </div>
-
-                        <div class="field-group">
-                            <label for="edit-context">Контекстное предложение (где встретилось?)</label>
-                            <input type="text" id="edit-context" class="input-styled" placeholder="Например: The switch drops the frame if the VLAN ID is invalid.">
-                        </div>
-
+                    <!-- Organization: Collection & Tags Row -->
+                    <div class="meta-inputs-grid">
                         <div class="field-row">
-                            <div class="field-group flex-2">
-                                <label for="edit-tags">Теги (через запятую)</label>
-                                <input type="text" id="edit-tags" class="input-styled" placeholder="general, phrasal-verb, networking">
-                                <div class="quick-tags" id="quick-tags-bar">
-                                    <span class="tag-chip" data-tag="general">#general</span>
-                                    <span class="tag-chip" data-tag="phrasal-verb">#phrasal-verb</span>
-                                    <span class="tag-chip" data-tag="idiom">#idiom</span>
-                                    <span class="tag-chip" data-tag="daily">#daily</span>
-                                    <span class="tag-chip" data-tag="tech">#tech</span>
-                                    <span class="tag-chip" data-tag="work">#work</span>
-                                </div>
+                            <div class="form-group flex-1">
+                                <label for="edit-collection">📁 Коллекция (папка):</label>
+                                <input type="text" id="edit-collection" list="collections-datalist" class="input-styled" value="General" placeholder="General, IT, Work...">
+                                <datalist id="collections-datalist"></datalist>
                             </div>
-
-                            <div class="field-group flex-1">
-                                <label for="edit-notes">Заметка / Мнемоника</label>
+                            <div class="form-group flex-1">
+                                <label for="edit-tags">🏷️ Теги (через запятую):</label>
+                                <input type="text" id="edit-tags" class="input-styled" placeholder="#phrasal-verb, #work, #daily" value="general">
+                            </div>
+                            <div class="form-group flex-1">
+                                <label for="edit-notes">💡 Заметка / Ассоциация:</label>
                                 <input type="text" id="edit-notes" class="input-styled" placeholder="Ассоциация...">
                             </div>
                         </div>
@@ -152,15 +182,32 @@
                     </div>
 
                     <div class="list-controls">
+                        <button id="batch-toggle-btn" class="btn btn-sm btn-outline batch-mode-btn" title="Режим множественного выбора">
+                            ☑️ Выбрать
+                        </button>
                         <div class="search-mini-box">
                             <input type="text" id="filter-input" placeholder="Фильтр по слову, переводу, контексту...">
                         </div>
                     </div>
                 </div>
 
+                <!-- Collections Filter Bar -->
+                <div class="collections-filter-wrap">
+                    <div class="filter-header-bar">
+                        <span class="filter-title">📁 Коллекции:</span>
+                        <button id="new-collection-btn" class="btn btn-xs btn-ghost">+ Новая папка</button>
+                    </div>
+                    <div id="collections-filter-bar" class="filter-chips-row">
+                        <button class="col-chip active" data-col="">Все коллекции</button>
+                    </div>
+                </div>
+
                 <!-- Active Tags Filter -->
-                <div id="tags-filter-bar" class="tags-filter-bar">
-                    <button class="filter-chip active" data-tag="">Все теги</button>
+                <div class="tags-filter-wrap">
+                    <span class="filter-title">🏷️ Теги:</span>
+                    <div id="tags-filter-bar" class="filter-chips-row">
+                        <button class="filter-chip active" data-tag="">Все теги</button>
+                    </div>
                 </div>
 
                 <!-- Cards Grid/List -->
@@ -173,32 +220,446 @@
                 </div>
             </section>
         </main>
+
+        <!-- VIEW 2: SRS Trainer Interactive View -->
+        <section id="srs-view" class="srs-view hidden">
+            <!-- SRS Top Bar -->
+            <header class="srs-topbar">
+                <div class="srs-topbar-left">
+                    <button id="srs-exit-btn" class="btn btn-sm btn-outline">← В словарь</button>
+                    <div class="srs-mode-switch">
+                        <button class="srs-tab active" data-mode="flashcards">📇 Карточки</button>
+                        <button class="srs-tab" data-mode="quiz">🎯 4 Варианта</button>
+                        <button class="srs-tab" data-mode="typing">✍️ Набор слова</button>
+                        <button class="srs-tab" data-mode="cloze">🧩 Пропуски</button>
+                        <button class="srs-tab" data-mode="dictation">🎧 Диктант</button>
+                    </div>
+                </div>
+
+                <div class="srs-topbar-center">
+                    <div class="srs-progress-container">
+                        <div id="srs-progress-fill" class="srs-progress-fill" style="width: 0%;"></div>
+                    </div>
+                    <span id="srs-counter" class="srs-counter">Карточка 0 из 0</span>
+                </div>
+
+                <div class="srs-topbar-right">
+                    <button id="srs-mix-btn" class="btn btn-sm btn-ghost" title="Умный микс дня: 10 новых + 10 повторов + 5 трудных слов">
+                        <span id="srs-mix-label">🎲 Микс дня: ВКЛ</span>
+                    </button>
+                    <button id="srs-dir-btn" class="btn btn-sm btn-secondary" title="Сменить направление">
+                        <span id="srs-dir-label">EN ➔ RU</span> ⇄
+                    </button>
+                </div>
+            </header>
+
+            <!-- SRS Main Interactive Arena -->
+            <div class="srs-arena">
+                <!-- Loading State -->
+                <div id="srs-loading" class="srs-state-box hidden">
+                    <div class="spinner"></div>
+                    <p>Загрузка карточек для тренировки...</p>
+                </div>
+
+                <!-- Empty State -->
+                <div id="srs-empty" class="srs-state-box hidden">
+                    <div class="srs-big-icon">🎉</div>
+                    <h3>На сегодня всё повторено!</h3>
+                    <p>В очереди нет слов, требующих интервального повторения.</p>
+                    <div class="srs-empty-buttons">
+                        <button id="srs-train-all-btn" class="btn btn-primary btn-lg">Тренировать все слова вне очереди</button>
+                        <button id="srs-empty-back-btn" class="btn btn-outline btn-lg">Вернуться в словарь</button>
+                    </div>
+                </div>
+
+                <!-- MODE 1: Flashcards -->
+                <div id="srs-mode-flashcards" class="srs-mode-container hidden">
+                    <div class="flashcard-wrapper" id="flashcard-flip-wrap">
+                        <div class="flashcard-inner" id="flashcard-inner">
+                            <!-- Card Front -->
+                            <div class="flashcard-face flashcard-front" id="flashcard-front">
+                                <div class="fc-badge-row">
+                                    <span class="fc-dir-badge" id="fc-front-dir-badge">EN ➔ RU</span>
+                                    <span class="fc-pos-badge" id="fc-front-pos">Adjective</span>
+                                </div>
+                                <div class="fc-center">
+                                    <h1 class="fc-main-term" id="fc-front-main">reluctant</h1>
+                                    <div class="fc-phonetic-row" id="fc-front-phonetic-wrap">
+                                        <span class="res-phonetic" id="fc-front-phonetic">/rɪˈlʌktənt/</span>
+                                        <button id="fc-front-audio-btn" class="icon-btn audio-round-btn" title="Озвучить (Ctrl+P / 🔊)">🔊</button>
+                                    </div>
+                                    <div class="fc-hint-wrapper">
+                                        <button id="fc-hint-btn" class="btn btn-xs btn-ghost">💡 Показать контекст</button>
+                                        <div id="fc-hint-box" class="fc-hint-content hidden"></div>
+                                    </div>
+                                </div>
+                                <div class="fc-footer-hint">
+                                    <kbd>Space</kbd> или клик по карточке — перевернуть
+                                </div>
+                            </div>
+
+                            <!-- Card Back -->
+                            <div class="flashcard-face flashcard-back" id="flashcard-back">
+                                <div class="fc-badge-row">
+                                    <span class="fc-dir-badge">ОТВЕТ</span>
+                                    <span class="fc-pos-badge" id="fc-back-pos">Adjective</span>
+                                </div>
+                                <div class="fc-back-content">
+                                    <div class="fc-back-top">
+                                        <h2 class="fc-back-term" id="fc-back-term">reluctant</h2>
+                                        <button id="fc-back-audio-btn" class="icon-btn audio-round-btn" title="Озвучить">🔊</button>
+                                    </div>
+                                    <div class="fc-back-translation" id="fc-back-translation">неохотный, нежелающий</div>
+                                    <div class="fc-back-detail-box" id="fc-back-def-box">
+                                        <span class="detail-label">Толкование:</span>
+                                        <p id="fc-back-def" class="detail-text"></p>
+                                    </div>
+                                    <div class="fc-back-detail-box" id="fc-back-context-box">
+                                        <span class="detail-label">Контекст:</span>
+                                        <p id="fc-back-context" class="detail-text"></p>
+                                    </div>
+                                    <div class="fc-back-detail-box" id="fc-back-notes-box">
+                                        <span class="detail-label">Заметка:</span>
+                                        <p id="fc-back-notes" class="detail-text"></p>
+                                    </div>
+                                </div>
+                            </div>
+                        </div>
+                    </div>
+
+                    <!-- Flip button (mobile accessible) -->
+                    <div id="fc-flip-btn-wrap" class="fc-flip-btn-wrap">
+                        <button id="fc-flip-btn" class="btn btn-primary btn-block btn-lg">Показать ответ (Space)</button>
+                    </div>
+
+                    <!-- Rating Buttons -->
+                    <div id="fc-rating-bar" class="srs-rating-bar hidden">
+                        <button class="btn-rate btn-rate-1" data-rating="1" title="Горячая клавиша: 1">
+                            <span class="rate-key">[1]</span>
+                            <span class="rate-name">Снова</span>
+                            <span class="rate-time">&lt; 1 мин</span>
+                        </button>
+                        <button class="btn-rate btn-rate-2" data-rating="2" title="Горячая клавиша: 2">
+                            <span class="rate-key">[2]</span>
+                            <span class="rate-name">Трудно</span>
+                            <span class="rate-time">1 день</span>
+                        </button>
+                        <button class="btn-rate btn-rate-3" data-rating="3" title="Горячая клавиша: 3">
+                            <span class="rate-key">[3]</span>
+                            <span class="rate-name">Хорошо</span>
+                            <span class="rate-time">3 дня</span>
+                        </button>
+                        <button class="btn-rate btn-rate-4" data-rating="4" title="Горячая клавиша: 4">
+                            <span class="rate-key">[4]</span>
+                            <span class="rate-name">Легко</span>
+                            <span class="rate-time">7 дней</span>
+                        </button>
+                    </div>
+                </div>
+
+                <!-- MODE 2: Multiple Choice Quiz (4 options) -->
+                <div id="srs-mode-quiz" class="srs-mode-container hidden">
+                    <div class="trainer-card quiz-card">
+                        <div class="trainer-header">
+                            <span class="mode-tag">🎯 Выбор из 4 вариантов</span>
+                            <span class="trainer-pos" id="quiz-pos"></span>
+                        </div>
+
+                        <div class="quiz-hero">
+                            <div class="quiz-prompt-row">
+                                <h2 id="quiz-term-display" class="quiz-term-display">word</h2>
+                                <button id="quiz-audio-btn" class="icon-btn audio-round-btn" title="Озвучить">🔊</button>
+                            </div>
+                            <div id="quiz-phonetic-display" class="res-phonetic"></div>
+                            <div id="quiz-context-hint" class="quiz-context-hint hidden"></div>
+                        </div>
+
+                        <div class="quiz-options-grid" id="quiz-options-grid">
+                            <!-- 4 option buttons generated dynamically -->
+                        </div>
+
+                        <div id="quiz-feedback-box" class="trainer-feedback-box hidden"></div>
+                        <div id="quiz-details-box" class="trainer-revealed-details hidden"></div>
+
+                        <div id="quiz-next-bar" class="quiz-next-bar hidden">
+                            <button id="quiz-next-btn" class="btn btn-primary btn-lg btn-block">Следующее слово (Enter / Space)</button>
+                        </div>
+                    </div>
+                </div>
+
+                <!-- MODE 3: Active Typing Mode (Ru -> En) -->
+                <div id="srs-mode-typing" class="srs-mode-container hidden">
+                    <div class="trainer-card">
+                        <div class="trainer-header">
+                            <span class="mode-tag">✍️ Набор слова на английском</span>
+                            <span class="trainer-pos" id="typing-pos"></span>
+                        </div>
+
+                        <div class="typing-hero">
+                            <span class="hint-label">Переведите на английский язык:</span>
+                            <h2 id="typing-prompt-ru" class="typing-prompt-ru">слово</h2>
+                            <div id="typing-context-hint" class="typing-context-hint hidden"></div>
+                        </div>
+
+                        <form id="typing-form" class="trainer-form">
+                            <div class="input-action-row">
+                                <input type="text" id="typing-input" class="input-styled input-hero" placeholder="Напечатайте английское слово или связку..." autocomplete="off" autocorrect="off" autocapitalize="off" spellcheck="false" autofocus>
+                                <button type="submit" id="typing-submit-btn" class="btn btn-primary">Проверить</button>
+                            </div>
+                        </form>
+
+                        <div id="typing-feedback-box" class="trainer-feedback-box hidden"></div>
+                        <div id="typing-details-box" class="trainer-revealed-details hidden"></div>
+
+                        <!-- Rating bar for typing -->
+                        <div id="typing-rating-bar" class="srs-rating-bar hidden"></div>
+                    </div>
+                </div>
+
+                <!-- MODE 4: Cloze Deletion -->
+                <div id="srs-mode-cloze" class="srs-mode-container hidden">
+                    <div class="trainer-card">
+                        <div class="trainer-header">
+                            <span class="mode-tag">🧩 Пропуски в контексте</span>
+                            <span class="trainer-pos" id="cloze-pos"></span>
+                        </div>
+
+                        <div class="cloze-sentence-display" id="cloze-sentence-display">
+                            The switch <span class="gap-placeholder">_____</span> the frame if invalid.
+                        </div>
+
+                        <div class="cloze-translation-hint">
+                            <span class="hint-label">Перевод целевого слова:</span>
+                            <strong id="cloze-target-translation">неохотный</strong>
+                        </div>
+
+                        <form id="cloze-form" class="trainer-form">
+                            <div class="input-action-row">
+                                <input type="text" id="cloze-input" class="input-styled input-hero" placeholder="Введите пропущенное слово..." autocomplete="off" autocorrect="off" autocapitalize="off" spellcheck="false" autofocus>
+                                <button type="submit" id="cloze-submit-btn" class="btn btn-primary">Проверить</button>
+                            </div>
+                        </form>
+
+                        <div id="cloze-feedback-box" class="trainer-feedback-box hidden"></div>
+                        <div id="cloze-details-box" class="trainer-revealed-details hidden"></div>
+
+                        <!-- Rating bar for cloze -->
+                        <div id="cloze-rating-bar" class="srs-rating-bar hidden"></div>
+                    </div>
+                </div>
+
+                <!-- MODE 5: Audio Dictation -->
+                <div id="srs-mode-dictation" class="srs-mode-container hidden">
+                    <div class="trainer-card">
+                        <div class="trainer-header">
+                            <span class="mode-tag">🎧 Аудио-диктант</span>
+                            <button id="dictation-replay-btn" class="btn btn-sm btn-ghost audio-replay-btn">
+                                🔊 Повторить звук <span class="kbd-sub"><kbd>Space</kbd></span>
+                            </button>
+                        </div>
+
+                        <div class="dictation-hero">
+                            <button id="dictation-big-play-btn" class="dictation-pulse-btn" title="Слушать произношение">
+                                🔊
+                            </button>
+                            <p class="dictation-instructions">Слушайте произношение нативного диктора и напечатайте слово</p>
+                        </div>
+
+                        <div class="dictation-hint-wrap">
+                            <button id="dictation-toggle-hint-btn" class="btn btn-xs btn-ghost">💡 Показать перевод-подсказку</button>
+                            <span id="dictation-hint-text" class="dictation-hint-text hidden"></span>
+                        </div>
+
+                        <form id="dictation-form" class="trainer-form">
+                            <div class="input-action-row">
+                                <input type="text" id="dictation-input" class="input-styled input-hero" placeholder="Напечатайте услышанное слово на английском..." autocomplete="off" autocorrect="off" autocapitalize="off" spellcheck="false" autofocus>
+                                <button type="submit" id="dictation-submit-btn" class="btn btn-primary">Проверить</button>
+                            </div>
+                        </form>
+
+                        <div id="dictation-feedback-box" class="trainer-feedback-box hidden"></div>
+                        <div id="dictation-details-box" class="trainer-revealed-details hidden"></div>
+
+                        <!-- Rating bar for dictation -->
+                        <div id="dictation-rating-bar" class="srs-rating-bar hidden"></div>
+                    </div>
+                </div>
+
+                <!-- Session Complete Summary Screen -->
+                <div id="srs-summary" class="srs-summary-card hidden">
+                    <div class="summary-trophy">🏆</div>
+                    <h2>Сессия завершена!</h2>
+                    <p class="summary-lead">Вы успешно закрепили знания и освежили долговременную память.</p>
+
+                    <div class="summary-metrics">
+                        <div class="metric-card">
+                            <span class="metric-val" id="sum-count">0</span>
+                            <span class="metric-desc">Повторено слов</span>
+                        </div>
+                        <div class="metric-card">
+                            <span class="metric-val text-success" id="sum-retention">100%</span>
+                            <span class="metric-desc">Успешность (Хорошо/Легко)</span>
+                        </div>
+                        <div class="metric-card">
+                            <span class="metric-val text-primary" id="sum-streak">🔥 1</span>
+                            <span class="metric-desc">Серия дней</span>
+                        </div>
+                    </div>
+
+                    <div class="summary-rates-bar" id="sum-rates-breakdown"></div>
+
+                    <div class="summary-buttons">
+                        <button id="sum-repeat-btn" class="btn btn-primary btn-lg">🔄 Повторить ещё сессию</button>
+                        <button id="sum-return-btn" class="btn btn-outline btn-lg">📚 Вернуться в словарь</button>
+                    </div>
+                </div>
+            </div>
+        </section>
+
+        <!-- Sticky Bulk Action Bar for Batch Selection Mode -->
+        <div id="batch-action-bar" class="batch-action-bar hidden">
+            <div class="batch-left">
+                <label class="batch-check-label">
+                    <input type="checkbox" id="batch-select-all" class="batch-master-checkbox">
+                    <span id="batch-count-label">Выбрано: 0</span>
+                </label>
+            </div>
+            <div class="batch-actions">
+                <button id="batch-move-btn" class="btn btn-sm btn-outline">📁 В коллекцию</button>
+                <button id="batch-tag-btn" class="btn btn-sm btn-outline">🏷️ Добавить тег</button>
+                <button id="batch-delete-btn" class="btn btn-sm btn-danger">🗑️ Удалить</button>
+                <button id="batch-cancel-btn" class="btn btn-sm btn-ghost">✕ Отмена</button>
+            </div>
+        </div>
+    </div>
+
+    <!-- Analytics & Activity Heatmap Modal -->
+    <div id="stats-modal" class="modal-backdrop hidden">
+        <div class="modal-window stats-modal-window">
+            <div class="modal-header">
+                <h3>📊 Аналитика обучения & Активность</h3>
+                <button id="close-stats-modal-btn" class="icon-btn">✕</button>
+            </div>
+            <div class="modal-body">
+                <!-- Streak & Core Stats Hero -->
+                <div class="stats-hero-grid">
+                    <div class="stat-kpi-card streak-kpi">
+                        <div class="kpi-icon">🔥</div>
+                        <div class="kpi-value" id="kpi-current-streak">0</div>
+                        <div class="kpi-label">Текущая серия дней</div>
+                        <div class="kpi-sub" id="kpi-longest-streak">Рекорд: 0 дней</div>
+                    </div>
+                    <div class="stat-kpi-card">
+                        <div class="kpi-icon">🎯</div>
+                        <div class="kpi-value text-success" id="kpi-retention-rate">100%</div>
+                        <div class="kpi-label">Точность запоминания</div>
+                        <div class="kpi-sub" id="kpi-total-reviews">Всего повторений: 0</div>
+                    </div>
+                    <div class="stat-kpi-card">
+                        <div class="kpi-icon">📚</div>
+                        <div class="kpi-value" id="kpi-total-words">0</div>
+                        <div class="kpi-label">Слов в словаре</div>
+                        <div class="kpi-sub" id="kpi-today-added">Сегодня добавлено: +0</div>
+                    </div>
+                    <div class="stat-kpi-card">
+                        <div class="kpi-icon">🎓</div>
+                        <div class="kpi-value text-accent" id="kpi-cefr-level">A1</div>
+                        <div class="kpi-label">Оценка уровня</div>
+                        <div class="kpi-sub" id="kpi-cefr-desc">Начальный словарный запас</div>
+                    </div>
+                </div>
+
+                <!-- GitHub-Style Contribution Heatmap -->
+                <div class="heatmap-section">
+                    <div class="heatmap-header">
+                        <h4>🟩 Календарь активности (GitHub-style Heatmap)</h4>
+                        <div class="heatmap-legend">
+                            <span>Меньше</span>
+                            <span class="legend-cell lvl-0" title="0 повторений"></span>
+                            <span class="legend-cell lvl-1" title="1 повторение"></span>
+                            <span class="legend-cell lvl-2" title="2-3 повторения"></span>
+                            <span class="legend-cell lvl-3" title="4+ повторений"></span>
+                            <span>Больше</span>
+                        </div>
+                    </div>
+                    <div class="heatmap-container-wrap">
+                        <div id="heatmap-grid" class="heatmap-grid">
+                            <!-- Heatmap cells generated dynamically -->
+                        </div>
+                    </div>
+                    <div class="heatmap-footer-note">
+                        <small>Цвет ячейки показывает количество пройденных тестов и интервальных повторений за день.</small>
+                    </div>
+                </div>
+
+                <!-- Mastery Distribution Progress -->
+                <div class="mastery-section">
+                    <h4>📈 Стадии освоения слов (SM-2 SRS)</h4>
+                    <div class="segmented-progress-bar">
+                        <div id="prog-mastered" class="prog-segment seg-mastered" style="width: 0%;" title="Выучено (интервал > 21 дня)"></div>
+                        <div id="prog-review" class="prog-segment seg-review" style="width: 0%;" title="Повторение"></div>
+                        <div id="prog-learning" class="prog-segment seg-learning" style="width: 0%;" title="В процессе (1-3 повтора)"></div>
+                        <div id="prog-new" class="prog-segment seg-new" style="width: 100%;" title="Новые слова"></div>
+                    </div>
+                    <div class="mastery-legend-row">
+                        <div class="m-legend-item"><span class="dot dot-mastered"></span> Выучено: <strong id="cnt-mastered">0</strong></div>
+                        <div class="m-legend-item"><span class="dot dot-review"></span> Закрепление: <strong id="cnt-review">0</strong></div>
+                        <div class="m-legend-item"><span class="dot dot-learning"></span> В процессе: <strong id="cnt-learning">0</strong></div>
+                        <div class="m-legend-item"><span class="dot dot-new"></span> Новые: <strong id="cnt-new">0</strong></div>
+                        <div class="m-legend-item text-danger"><span class="dot dot-leech"></span> Трудные слова: <strong id="cnt-leeches">0</strong></div>
+                    </div>
+                </div>
+            </div>
+            <div class="modal-footer">
+                <button id="close-stats-btn" class="btn btn-primary">Закрыть</button>
+            </div>
+        </div>
     </div>
 
     <!-- Edit Card Modal -->
     <div id="edit-modal" class="modal-backdrop hidden">
         <div class="modal-window">
             <div class="modal-header">
-                <h3>Редактирование карточки</h3>
+                <h3>✏️ Редактировать карточку</h3>
                 <button id="close-modal-btn" class="icon-btn">✕</button>
             </div>
             <div class="modal-body">
                 <input type="hidden" id="modal-card-id">
                 <div class="form-group">
-                    <label>Слово / Фраза</label>
-                    <input type="text" id="modal-term" class="input-styled">
+                    <label>Слово / Выражение (EN)</label>
+                    <input type="text" id="modal-term" class="input-styled" required>
                 </div>
                 <div class="form-group">
-                    <label>Перевод на русский</label>
-                    <input type="text" id="modal-translation" class="input-styled">
+                    <label>Перевод (RU)</label>
+                    <input type="text" id="modal-translation" class="input-styled" required>
                 </div>
                 <div class="form-group">
                     <label>Контекстное предложение</label>
-                    <input type="text" id="modal-context" class="input-styled">
+                    <textarea id="modal-context" class="input-styled" rows="2"></textarea>
+                </div>
+                <div class="field-row">
+                    <div class="form-group flex-1">
+                        <label>Транскрипция (IPA)</label>
+                        <input type="text" id="modal-phonetic" class="input-styled">
+                    </div>
+                    <div class="form-group flex-1">
+                        <label>Часть речи</label>
+                        <input type="text" id="modal-pos" class="input-styled">
+                    </div>
                 </div>
                 <div class="form-group">
-                    <label>Теги</label>
-                    <input type="text" id="modal-tags" class="input-styled">
+                    <label>Английское толкование</label>
+                    <textarea id="modal-def" class="input-styled" rows="2"></textarea>
+                </div>
+                <div class="field-row">
+                    <div class="form-group flex-1">
+                        <label>Коллекция (Папка)</label>
+                        <input type="text" id="modal-collection" class="input-styled">
+                    </div>
+                    <div class="form-group flex-1">
+                        <label>Теги</label>
+                        <input type="text" id="modal-tags" class="input-styled">
+                    </div>
                 </div>
                 <div class="form-group">
                     <label>Заметки / Мнемоника</label>
@@ -212,6 +673,135 @@
         </div>
     </div>
 
+    <!-- Export Modal -->
+    <div id="export-modal" class="modal-backdrop hidden">
+        <div class="modal-window export-modal-window">
+            <div class="modal-header">
+                <h3>📤 Экспорт словаря</h3>
+                <button id="close-export-modal-btn" class="icon-btn">✕</button>
+            </div>
+            <div class="modal-body">
+                <p class="modal-lead" id="export-modal-desc">Выберите удобный формат для выгрузки карточек:</p>
+                <div class="export-grid">
+                    <div class="export-tile" data-format="csv">
+                        <div class="export-tile-icon">📊</div>
+                        <div class="export-tile-info">
+                            <h4>CSV (Excel / Sheets)</h4>
+                            <p>Таблица со всеми полями, переводами и примерами (UTF-8 BOM для русского языка).</p>
+                        </div>
+                        <button class="btn btn-sm btn-primary">Скачать</button>
+                    </div>
+
+                    <div class="export-tile" data-format="anki">
+                        <div class="export-tile-icon">🗃️</div>
+                        <div class="export-tile-info">
+                            <h4>Колода для Anki (.tsv)</h4>
+                            <p>Готовый файл для импорта в Anki с транскрипцией, озвучкой и контекстом.</p>
+                        </div>
+                        <button class="btn btn-sm btn-primary">Скачать</button>
+                    </div>
+
+                    <div class="export-tile" data-format="json">
+                        <div class="export-tile-icon">📋</div>
+                        <div class="export-tile-info">
+                            <h4>JSON (Полный архив)</h4>
+                            <p>Полная структурированная резервная копия данных словаря.</p>
+                        </div>
+                        <button class="btn btn-sm btn-primary">Скачать</button>
+                    </div>
+
+                    <div class="export-tile" data-format="md">
+                        <div class="export-tile-icon">📝</div>
+                        <div class="export-tile-info">
+                            <h4>Markdown (.md)</h4>
+                            <p>Красивый структурированный конспект для Obsidian, Notion или чтения.</p>
+                        </div>
+                        <button class="btn btn-sm btn-primary">Скачать</button>
+                    </div>
+                </div>
+            </div>
+            <div class="modal-footer">
+                <span id="export-scope-label" class="text-dim">Объём экспорта: все карточки</span>
+                <button id="export-cancel-btn" class="btn btn-outline">Закрыть</button>
+            </div>
+        </div>
+    </div>
+
+    <!-- Move Collection Modal -->
+    <div id="move-col-modal" class="modal-backdrop hidden">
+        <div class="modal-window modal-sm">
+            <div class="modal-header">
+                <h3>📁 Переместить в коллекцию</h3>
+                <button id="close-move-modal-btn" class="icon-btn">✕</button>
+            </div>
+            <div class="modal-body">
+                <p class="modal-lead" id="move-modal-count-label">Выберите коллекцию для выбранных карточек:</p>
+                <div class="form-group">
+                    <label for="move-col-input">Название коллекции</label>
+                    <input type="text" id="move-col-input" list="move-collections-datalist" class="input-styled" placeholder="Например: Разговорный">
+                    <datalist id="move-collections-datalist"></datalist>
+                </div>
+                <div class="quick-tags" id="move-col-quick-list"></div>
+            </div>
+            <div class="modal-footer">
+                <button id="move-col-cancel-btn" class="btn btn-outline">Отмена</button>
+                <button id="move-col-confirm-btn" class="btn btn-primary">Переместить</button>
+            </div>
+        </div>
+    </div>
+
+    <!-- New Collection Modal -->
+    <div id="new-col-modal" class="modal-backdrop hidden">
+        <div class="modal-window modal-sm">
+            <div class="modal-header">
+                <h3>📁 Новая коллекция</h3>
+                <button id="close-new-col-modal-btn" class="icon-btn">✕</button>
+            </div>
+            <div class="modal-body">
+                <div class="form-group">
+                    <label for="new-col-name-input">Название новой коллекции</label>
+                    <input type="text" id="new-col-name-input" class="input-styled" placeholder="Например: Сериалы / Netflix">
+                </div>
+            </div>
+            <div class="modal-footer">
+                <button id="new-col-cancel-btn" class="btn btn-outline">Отмена</button>
+                <button id="new-col-save-btn" class="btn btn-primary">Создать</button>
+            </div>
+        </div>
+    </div>
+
+    <!-- Change Password Modal -->
+    <div id="change-password-modal" class="modal-backdrop hidden">
+        <div class="modal-window modal-sm">
+            <div class="modal-header">
+                <h3>🔑 Смена пароля</h3>
+                <button id="close-change-pwd-btn" class="icon-btn">✕</button>
+            </div>
+            <form id="change-password-form">
+                <div class="modal-body">
+                    <div class="form-group">
+                        <label for="current-password-input">Текущий пароль</label>
+                        <input type="password" id="current-password-input" class="input-styled" autocomplete="current-password" required placeholder="••••••••">
+                    </div>
+                    <div class="form-group">
+                        <label for="new-password-input">Новый пароль</label>
+                        <input type="password" id="new-password-input" class="input-styled" autocomplete="new-password" required minlength="6" placeholder="Минимум 6 символов">
+                    </div>
+                    <div class="form-group">
+                        <label for="confirm-password-input">Подтвердите новый пароль</label>
+                        <input type="password" id="confirm-password-input" class="input-styled" autocomplete="new-password" required minlength="6" placeholder="Повторите новый пароль">
+                    </div>
+                    <div id="change-pwd-error" class="error-banner hidden"></div>
+                    <div id="change-pwd-success" class="success-banner hidden"></div>
+                </div>
+                <div class="modal-footer">
+                    <button type="button" id="change-pwd-cancel-btn" class="btn btn-outline">Отмена</button>
+                    <button type="submit" id="change-pwd-save-btn" class="btn btn-primary">Сохранить</button>
+                </div>
+            </form>
+        </div>
+    </div>
+
     <!-- Audio Element for native streaming -->
     <audio id="global-audio-player" preload="none"></audio>
 

app/static/manifest.json

@@ -0,0 +1,27 @@
+{
+  "name": "Notes English — Personal Vocabulary",
+  "short_name": "Notes",
+  "description": "Персональный словарь английского языка с переводом, транскрипцией и произношением.",
+  "start_url": "/",
+  "display": "standalone",
+  "background_color": "#0f172a",
+  "theme_color": "#0f172a",
+  "lang": "ru",
+  "orientation": "portrait-primary",
+  "icons": [
+    {
+      "src": "/static/icons/icon-192.png",
+      "sizes": "192x192",
+      "type": "image/png",
+      "purpose": "any maskable"
+    },
+    {
+      "src": "/static/icons/icon-512.png",
+      "sizes": "512x512",
+      "type": "image/png",
+      "purpose": "any maskable"
+    }
+  ],
+  "categories": ["education", "productivity"],
+  "screenshots": []
+}

app/static/sw.js

@@ -0,0 +1,101 @@
+// Service Worker for Notes English PWA (Stage 2)
+// Strategy: Cache-first for static assets, Network-first for API calls.
+
+const CACHE_NAME = 'notes-v2.0';
+const OFFLINE_URL = '/';
+
+const PRECACHE_URLS = [
+  '/',
+  '/static/css/style.css',
+  '/static/js/app.js',
+  '/manifest.json',
+];
+
+// -----------------------------------------------------------------------
+// Install: pre-cache core assets
+// -----------------------------------------------------------------------
+self.addEventListener('install', (event) => {
+  event.waitUntil(
+    caches.open(CACHE_NAME).then((cache) => {
+      return cache.addAll(PRECACHE_URLS);
+    }).then(() => self.skipWaiting())
+  );
+});
+
+// -----------------------------------------------------------------------
+// Activate: delete old caches
+// -----------------------------------------------------------------------
+self.addEventListener('activate', (event) => {
+  event.waitUntil(
+    caches.keys().then((keys) => {
+      return Promise.all(
+        keys
+          .filter((key) => key !== CACHE_NAME)
+          .map((key) => caches.delete(key))
+      );
+    }).then(() => self.clients.claim())
+  );
+});
+
+// -----------------------------------------------------------------------
+// Fetch: strategy based on request type
+// -----------------------------------------------------------------------
+self.addEventListener('fetch', (event) => {
+  const { request } = event;
+  const url = new URL(request.url);
+
+  // Skip cross-origin requests
+  if (url.origin !== location.origin) return;
+
+  // API calls → Network-first (never serve API from cache)
+  if (url.pathname.startsWith('/api/')) {
+    event.respondWith(
+      fetch(request).catch(() => {
+        return new Response(
+          JSON.stringify({ error: 'Offline. Please check your connection.' }),
+          { status: 503, headers: { 'Content-Type': 'application/json' } }
+        );
+      })
+    );
+    return;
+  }
+
+  // Static assets (CSS, JS, icons) → Cache-first
+  if (
+    url.pathname.startsWith('/static/') ||
+    url.pathname === '/manifest.json' ||
+    url.pathname === '/sw.js'
+  ) {
+    event.respondWith(
+      caches.match(request).then((cached) => {
+        return cached || fetch(request).then((response) => {
+          if (response.ok) {
+            const clone = response.clone();
+            caches.open(CACHE_NAME).then((cache) => cache.put(request, clone));
+          }
+          return response;
+        });
+      })
+    );
+    return;
+  }
+
+  // HTML navigation (SPA root) → Network-first with offline fallback
+  event.respondWith(
+    fetch(request)
+      .then((response) => {
+        if (response.ok) {
+          const clone = response.clone();
+          caches.open(CACHE_NAME).then((cache) => cache.put(request, clone));
+        }
+        return response;
+      })
+      .catch(() => {
+        return caches.match(OFFLINE_URL).then((cached) => {
+          return cached || new Response('<h1>Offline</h1><p>Please check your connection.</p>', {
+            headers: { 'Content-Type': 'text/html' },
+          });
+        });
+      })
+  );
+});

tests/test_api.py

@@ -13,7 +13,7 @@ os.environ["ADMIN_PASSWORD"] = "testpass12345"
 from app.main import app
 from app import config
 from app.database import init_db, get_db
-from app.auth import hash_password, verify_password, create_user, authenticate_user, ensure_admin_user
+from app.auth import hash_password, verify_password, create_user, authenticate_user, ensure_admin_user, change_user_password
 
 config.ADMIN_USERNAME = "testadmin"
 config.ADMIN_PASSWORD = "testpass12345"
@@ -57,6 +57,24 @@ def test_unauthenticated_access_blocked():
     resp = client.post("/api/cards", json={"term": "apple", "translation": "яблоко"})
     assert resp.status_code == 401
 
+    resp = client.get("/api/collections")
+    assert resp.status_code == 401
+
+    resp = client.post("/api/cards/batch", json={"card_ids": [1], "action": "delete"})
+    assert resp.status_code == 401
+
+    resp = client.get("/api/export/csv")
+    assert resp.status_code == 401
+
+    resp = client.get("/api/srs/queue")
+    assert resp.status_code == 401
+
+    resp = client.get("/api/srs/stats")
+    assert resp.status_code == 401
+
+    resp = client.post("/api/srs/review", json={"card_id": 1, "rating": 3})
+    assert resp.status_code == 401
+
 def test_login_and_card_crud_workflow():
     # 1. Login with testadmin
     resp = client.post("/api/login", json={"username": "testadmin", "password": "testpass12345"})
@@ -173,3 +191,316 @@ def test_lookup_endpoint_authenticated():
     assert "phonetic" in data
     assert len(data["translation"]) > 0
 
+def test_collections_and_batch_operations():
+    # Login
+    client.post("/api/login", json={"username": "testadmin", "password": "testpass12345"})
+
+    # Create 3 cards in different collections
+    c1 = client.post("/api/cards", json={
+        "term": "ubiquitous",
+        "translation": "вездесущий",
+        "collection": "Academic",
+        "tags": "vocab, tech"
+    }).json()
+
+    c2 = client.post("/api/cards", json={
+        "term": "perseverance",
+        "translation": "настойчивость",
+        "collection": "Academic",
+        "tags": "character"
+    }).json()
+
+    c3 = client.post("/api/cards", json={
+        "term": "bite the bullet",
+        "translation": "стиснуть зубы",
+        "collection": "Idioms",
+        "tags": "idioms, daily"
+    }).json()
+
+    # Test GET /api/collections
+    resp = client.get("/api/collections")
+    assert resp.status_code == 200
+    cols = resp.json()
+    col_names = {c["name"]: c["count"] for c in cols}
+    assert "Academic" in col_names and col_names["Academic"] >= 2
+    assert "Idioms" in col_names and col_names["Idioms"] >= 1
+
+    # Test filter by collection in /api/cards
+    resp = client.get("/api/cards?collection=Academic")
+    assert resp.status_code == 200
+    academic_cards = resp.json()
+    assert all(c["collection"] == "Academic" for c in academic_cards["cards"])
+    assert any(c["id"] == c1["id"] for c in academic_cards["cards"])
+    assert any(c["id"] == c2["id"] for c in academic_cards["cards"])
+    assert not any(c["id"] == c3["id"] for c in academic_cards["cards"])
+
+    # Test Batch set_collection
+    batch_resp = client.post("/api/cards/batch", json={
+        "card_ids": [c1["id"], c2["id"]],
+        "action": "set_collection",
+        "value": "Advanced English"
+    })
+    assert batch_resp.status_code == 200
+    assert batch_resp.json()["affected"] == 2
+
+    # Verify collection updated
+    card1_check = client.get("/api/cards?search=ubiquitous").json()["cards"][0]
+    assert card1_check["collection"] == "Advanced English"
+
+    # Test Batch add_tags
+    batch_resp = client.post("/api/cards/batch", json={
+        "card_ids": [c1["id"], c2["id"]],
+        "action": "add_tags",
+        "value": "stage2, vocabulary"
+    })
+    assert batch_resp.status_code == 200
+    card1_tags = client.get("/api/cards?search=ubiquitous").json()["cards"][0]["tags"]
+    assert "stage2" in card1_tags
+    assert "vocabulary" in card1_tags
+
+    # Test Batch delete
+    batch_resp = client.post("/api/cards/batch", json={
+        "card_ids": [c1["id"], c2["id"], c3["id"]],
+        "action": "delete"
+    })
+    assert batch_resp.status_code == 200
+    assert batch_resp.json()["affected"] == 3
+
+    # Verify deleted
+    all_cards = client.get("/api/cards").json()["cards"]
+    deleted_ids = {c1["id"], c2["id"], c3["id"]}
+    assert not any(c["id"] in deleted_ids for c in all_cards)
+
+def test_export_endpoints():
+    client.post("/api/login", json={"username": "testadmin", "password": "testpass12345"})
+
+    # Create a test card with context sentence for cloze
+    card_resp = client.post("/api/cards", json={
+        "term": "serendipity",
+        "translation": "счастливая случайность",
+        "context_sentence": "Finding this book was pure serendipity.",
+        "phonetic": "ˌser.ənˈdɪp.ə.ti",
+        "part_of_speech": "Noun",
+        "definition_en": "Good luck in making unexpected discoveries",
+        "collection": "Vocabulary",
+        "tags": "literature, rare",
+        "notes": "Beautiful English word"
+    })
+    card = card_resp.json()
+
+    # 1. CSV Export
+    resp = client.get("/api/export/csv")
+    assert resp.status_code == 200
+    assert "text/csv" in resp.headers["Content-Type"]
+    assert resp.content.startswith(b"\xef\xbb\xbf")  # UTF-8 BOM
+    csv_text = resp.content.decode("utf-8-sig")
+    assert "serendipity" in csv_text
+    assert "счастливая случайность" in csv_text
+    assert "term,translation,context,phonetic" in csv_text
+
+    # 2. JSON Export
+    resp = client.get("/api/export/json")
+    assert resp.status_code == 200
+    assert "application/json" in resp.headers["Content-Type"]
+    json_data = resp.json()
+    assert "cards" in json_data
+    assert any(c["term"] == "serendipity" for c in json_data["cards"])
+
+    # 3. Anki Export
+    resp = client.get("/api/export/anki")
+    assert resp.status_code == 200
+    anki_text = resp.text
+    assert "#separator:tab" in anki_text
+    assert "#html:true" in anki_text
+    assert "{{c1::serendipity}}" in anki_text  # Cloze verified
+    assert "collection_Vocabulary" in anki_text
+
+    # 4. Markdown Export
+    resp = client.get("/api/export/markdown")
+    assert resp.status_code == 200
+    md_text = resp.text
+    assert "| **serendipity** |" in md_text
+    assert "### serendipity" in md_text
+
+    # Filter export by collection
+    resp_filtered = client.get("/api/export/json?collection=NonExistentCollection")
+    assert resp_filtered.status_code == 200
+    assert len(resp_filtered.json()["cards"]) == 0
+
+    # Clean up
+    client.delete(f"/api/cards/{card['id']}")
+
+def test_sm2_algorithm_unit():
+    from app.srs import calculate_sm2, calculate_next_review
+    from datetime import datetime, timezone
+
+    base = datetime(2026, 9, 22, 12, 0, 0, tzinfo=timezone.utc)
+
+    # Rating 1 (Again)
+    res1 = calculate_sm2(1, reps=2, interval=6, ease=2.5, base_time=base)
+    assert res1["srs_reps"] == 0
+    assert res1["srs_interval"] == 1
+    assert res1["srs_ease"] == 2.3
+    assert res1["srs_state"] == "learning"
+
+    # Rating 2 (Hard)
+    res2 = calculate_sm2(2, reps=1, interval=1, ease=2.5, base_time=base)
+    assert res2["srs_reps"] == 2
+    assert res2["srs_interval"] == 1
+    assert res2["srs_ease"] == 2.35
+    assert res2["srs_state"] == "learning"
+
+    res2_later = calculate_sm2(2, reps=2, interval=10, ease=2.5, base_time=base)
+    assert res2_later["srs_reps"] == 3
+    assert res2_later["srs_interval"] == 12  # round(10 * 1.2) = 12
+    assert res2_later["srs_state"] == "review"  # reps >= 3
+
+    # Rating 3 (Good)
+    res3_first = calculate_sm2(3, reps=0, interval=0, ease=2.5, base_time=base)
+    assert res3_first["srs_reps"] == 1
+    assert res3_first["srs_interval"] == 1
+    assert res3_first["srs_state"] == "review"
+
+    res3_second = calculate_sm2(3, reps=1, interval=1, ease=2.5, base_time=base)
+    assert res3_second["srs_reps"] == 2
+    assert res3_second["srs_interval"] == 6
+    assert res3_second["srs_state"] == "review"
+
+    res3_third = calculate_sm2(3, reps=2, interval=6, ease=2.5, base_time=base)
+    assert res3_third["srs_reps"] == 3
+    assert res3_third["srs_interval"] == 15  # round(6 * 2.5) = 15
+
+    res3_mastered = calculate_sm2(3, reps=3, interval=15, ease=2.5, base_time=base)
+    assert res3_mastered["srs_reps"] == 4
+    assert res3_mastered["srs_interval"] == 38  # round(15 * 2.5) = 38 >= 21
+    assert res3_mastered["srs_state"] == "mastered"
+
+    # Rating 4 (Easy)
+    res4_first = calculate_sm2(4, reps=0, interval=0, ease=2.5, base_time=base)
+    assert res4_first["srs_reps"] == 1
+    assert res4_first["srs_interval"] == 4
+    assert res4_first["srs_ease"] == 2.65
+
+    # Boundary checks: Ease minimum 1.3
+    res_min_ease = calculate_sm2(1, reps=0, interval=1, ease=1.35, base_time=base)
+    assert res_min_ease["srs_ease"] == 1.3
+
+    # Boundary checks: Ease maximum 3.0
+    res_max_ease = calculate_sm2(4, reps=1, interval=4, ease=2.95, base_time=base)
+    assert res_max_ease["srs_ease"] == 3.0
+
+    # Invalid rating
+    with pytest.raises(ValueError):
+        calculate_sm2(0)
+    with pytest.raises(ValueError):
+        calculate_sm2(5)
+
+def test_srs_endpoints_flow():
+    client.post("/api/login", json={"username": "testadmin", "password": "testpass12345"})
+
+    # Create a new card
+    card_resp = client.post("/api/cards", json={
+        "term": "meticulous",
+        "translation": "дотошный, педантичный",
+        "collection": "General"
+    })
+    card = card_resp.json()
+    card_id = card["id"]
+    assert card["srs_state"] == "new"
+
+    # 1. Check /api/srs/queue
+    resp = client.get("/api/srs/queue")
+    assert resp.status_code == 200
+    queue_data = resp.json()
+    assert any(c["id"] == card_id for c in queue_data["cards"])
+
+    # 2. Check /api/srs/stats before review
+    resp = client.get("/api/srs/stats")
+    assert resp.status_code == 200
+    stats_before = resp.json()
+    assert "new_cards" in stats_before
+    assert "learning" in stats_before
+    assert "mastered" in stats_before
+    assert "streak_days" in stats_before
+
+    # 3. Submit Review: Rating 3 (Good)
+    rev_resp = client.post("/api/srs/review", json={"card_id": card_id, "rating": 3})
+    assert rev_resp.status_code == 200
+    rev_data = rev_resp.json()
+    assert rev_data["status"] == "ok"
+    updated_card = rev_data["card"]
+    assert updated_card["srs_reps"] == 1
+    assert updated_card["srs_interval"] == 1
+    assert updated_card["srs_state"] == "review"
+
+    # 4. Check stats after review: total_reviews incremented, streak >= 1
+    stats_after = client.get("/api/srs/stats").json()
+    assert stats_after["total_reviews"] >= stats_before["total_reviews"] + 1
+    assert stats_after["streak_days"] >= 1
+
+    # 5. Review invalid rating
+    bad_rev = client.post("/api/srs/review", json={"card_id": card_id, "rating": 99})
+    assert bad_rev.status_code in (400, 422)
+
+    # 6. Review non-existent card
+    missing_rev = client.post("/api/srs/review", json={"card_id": 999999, "rating": 3})
+    assert missing_rev.status_code == 404
+
+    # Clean up
+    client.delete(f"/api/cards/{card_id}")
+
+def test_pwa_routes_response():
+    resp_m = client.get("/manifest.json")
+    assert resp_m.status_code in (200, 404)
+    if resp_m.status_code == 200:
+        assert resp_m.headers["Content-Type"].startswith("application/manifest+json")
+
+    resp_sw = client.get("/sw.js")
+    assert resp_sw.status_code in (200, 404)
+    if resp_sw.status_code == 200:
+        assert resp_sw.headers["Service-Worker-Allowed"] == "/"
+        assert "no-cache" in resp_sw.headers["Cache-Control"]
+
+
+def test_change_password_flow():
+    # 1. Create a dedicated user for password change test
+    test_uid = create_user("pwd_user", "old_secret_pass_123")
+    assert test_uid > 0
+
+    # 2. Login
+    login_resp = client.post("/api/login", json={"username": "pwd_user", "password": "old_secret_pass_123"})
+    assert login_resp.status_code == 200
+
+    # 3. Try to change with wrong old password
+    fail_resp = client.post("/api/change-password", json={
+        "old_password": "wrong_old_password",
+        "new_password": "brand_new_pass_456"
+    })
+    assert fail_resp.status_code == 400
+
+    # 4. Try to change with short new password (<6 chars)
+    short_resp = client.post("/api/change-password", json={
+        "old_password": "old_secret_pass_123",
+        "new_password": "123"
+    })
+    assert short_resp.status_code == 422
+
+    # 5. Successfully change password
+    ok_resp = client.post("/api/change-password", json={
+        "old_password": "old_secret_pass_123",
+        "new_password": "brand_new_pass_456"
+    })
+    assert ok_resp.status_code == 200
+    assert ok_resp.json()["status"] == "ok"
+
+    # 6. Verify old password no longer authenticates
+    old_auth = authenticate_user("pwd_user", "old_secret_pass_123")
+    assert old_auth is None
+
+    # 7. Verify new password authenticates
+    new_auth = authenticate_user("pwd_user", "brand_new_pass_456")
+    assert new_auth is not None
+    assert new_auth["username"] == "pwd_user"
+
+
+