/* ========================================
   Страница урока
======================================== */

/* Навигация урока */
.lesson-navbar {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: 1000;
    background: var(--white);
    box-shadow: var(--shadow-sm);
    height: 64px;
}

.lesson-navbar .nav-container {
    height: 64px;
}

.lesson-logo {
    margin-right: 16px;
}

.lesson-logo .logo-img {
    height: 28px;
}

.back-to-course {
    display: flex;
    align-items: center;
    gap: 8px;
    color: var(--gray-dark);
    font-weight: 600;
    transition: color var(--transition-fast);
}

.back-to-course:hover {
    color: var(--primary);
}

.back-icon {
    font-size: 20px;
}

.lesson-nav-info {
    display: flex;
    align-items: center;
    gap: 16px;
}

.lesson-nav-title {
    font-weight: 700;
    color: var(--dark);
}

.lesson-nav-progress {
    width: 150px;
}

.nav-progress-bar {
    height: 6px;
    background: var(--gray-light);
    border-radius: 3px;
    overflow: hidden;
}

.nav-progress-fill {
    height: 100%;
    background: var(--gradient-primary);
    border-radius: 3px;
    transition: width var(--transition-slow);
}

.lesson-nav-actions {
    display: flex;
    gap: 8px;
}

/* ========================================
   Основной контент
======================================== */

.lesson-main {
    padding: 88px 0 60px;
    background: var(--light);
    min-height: 100vh;
}

.lesson-layout {
    display: grid;
    grid-template-columns: 1fr 320px;
    gap: 32px;
    align-items: start;
}

.lesson-content {
    background: var(--white);
    border-radius: var(--radius-lg);
    box-shadow: var(--shadow-sm);
    overflow: hidden;
}

/* Заголовок урока */
.lesson-header {
    padding: 32px;
    border-bottom: 1px solid var(--gray-light);
}

.lesson-module-badge {
    display: inline-block;
    background: var(--primary-light);
    color: var(--primary-dark);
    padding: 6px 14px;
    border-radius: var(--radius-xl);
    font-size: 12px;
    font-weight: 700;
    margin-bottom: 12px;
}

.lesson-title {
    font-size: 32px;
    font-weight: 800;
    margin-bottom: 12px;
    color: var(--dark);
}

.lesson-description {
    font-size: 16px;
    color: var(--gray-dark);
    line-height: 1.6;
}

/* ========================================
   Вкладки
======================================== */

.lesson-tabs {
    display: flex;
    border-bottom: 1px solid var(--gray-light);
    background: var(--light);
}

.tab-btn {
    flex: 1;
    display: inline-flex;
    flex-direction: row;
    flex-wrap: nowrap;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 16px 24px;
    background: none;
    border: none;
    font-family: var(--font-main);
    font-size: 15px;
    font-weight: 700;
    color: var(--gray-dark);
    cursor: pointer;
    transition: all var(--transition-fast);
    position: relative;
    white-space: nowrap;
}

.tab-btn:hover {
    color: var(--primary);
    background: rgba(108, 92, 231, 0.05);
}

.tab-btn.active {
    color: var(--primary);
    background: var(--white);
}

.tab-btn.active::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--primary);
}

.tab-content {
    padding: 32px;
}

.tab-pane {
    display: none;
}

.tab-pane.active {
    display: block;
    animation: fadeIn 0.3s ease;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

/* ========================================
   Видео
======================================== */

.video-container {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.video-platform-switch {
    display: flex;
    align-items: center;
    gap: 16px;
    flex-wrap: wrap;
}

.switch-label {
    font-size: 14px;
    color: var(--gray-dark);
}

.switch-buttons {
    display: flex;
    gap: 8px;
}

.switch-btn {
    display: flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    background: var(--light);
    border: 2px solid var(--gray-light);
    border-radius: var(--radius-xl);
    font-family: var(--font-main);
    font-size: 14px;
    font-weight: 600;
    color: var(--gray-dark);
    cursor: pointer;
    transition: all var(--transition-fast);
}

.switch-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.switch-btn.active {
    background: var(--primary);
    border-color: var(--primary);
    color: var(--white);
}

.platform-icon {
    font-size: 14px;
}

.video-player {
    width: 100%;
}

.video-player.hidden {
    display: none;
}

.video-wrapper {
    position: relative;
    padding-bottom: 56.25%;
    height: 0;
    overflow: hidden;
    border-radius: var(--radius-md);
    background: var(--dark);
}

.video-wrapper iframe {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
}

.video-note {
    background: linear-gradient(135deg, #FFF9E6 0%, #FFF3CD 100%);
    padding: 16px 20px;
    border-radius: var(--radius-md);
    border-left: 4px solid #FFD93D;
    font-size: 14px;
    color: var(--dark);
}

/* ========================================
   Текстовые материалы
======================================== */

.text-content h2 {
    font-size: 24px;
    margin-bottom: 24px;
    color: var(--dark);
}

.vocabulary-section {
    margin-bottom: 32px;
}

.vocabulary-section h3 {
    font-size: 18px;
    margin-bottom: 16px;
    color: var(--dark);
}

.vocab-cards {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 16px;
}

.vocab-card {
    background: var(--light);
    border-radius: var(--radius-md);
    padding: 20px;
    text-align: center;
    position: relative;
    transition: all var(--transition-normal);
}

.vocab-card:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-md);
}

.vocab-english {
    font-size: 20px;
    font-weight: 800;
    color: var(--primary);
    margin-bottom: 4px;
}

.vocab-transcription {
    font-size: 14px;
    color: var(--gray-dark);
    font-family: monospace;
    margin-bottom: 8px;
}

.vocab-russian {
    font-size: 16px;
    color: var(--dark);
}

.play-audio-btn {
    position: absolute;
    top: 12px;
    right: 12px;
    width: 32px;
    height: 32px;
    background: var(--white);
    border: none;
    border-radius: 50%;
    font-size: 16px;
    cursor: pointer;
    box-shadow: var(--shadow-sm);
    transition: transform var(--transition-fast);
}

.play-audio-btn:hover {
    transform: scale(1.1);
}

/* Диалоги */
.dialog-example {
    background: var(--light);
    border-radius: var(--radius-md);
    padding: 24px;
}

.dialog-line {
    display: grid;
    grid-template-columns: 40px 1fr;
    gap: 8px;
    margin-bottom: 16px;
    padding-bottom: 16px;
    border-bottom: 1px solid var(--gray-light);
}

.dialog-line:last-child {
    margin-bottom: 0;
    padding-bottom: 0;
    border-bottom: none;
}

.speaker {
    font-weight: 800;
    color: var(--primary);
}

.english {
    font-size: 16px;
    font-weight: 700;
    color: var(--dark);
    display: block;
    margin-bottom: 4px;
}

.russian {
    font-size: 14px;
    color: var(--gray-dark);
    display: block;
}

/* Подсказка */
.tip-box {
    display: flex;
    gap: 16px;
    background: linear-gradient(135deg, #E8F5E9 0%, #C8E6C9 100%);
    border-radius: var(--radius-md);
    padding: 20px;
    border-left: 4px solid var(--accent-beginners);
}

.tip-icon {
    font-size: 24px;
}

.tip-content {
    font-size: 14px;
    line-height: 1.6;
}

/* ========================================
   Квиз
======================================== */

.quiz-container {
    max-width: 600px;
    margin: 0 auto;
}

.quiz-header {
    text-align: center;
    margin-bottom: 32px;
}

.quiz-header h2 {
    margin-bottom: 20px;
}

.quiz-progress {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.quiz-current {
    font-size: 14px;
    color: var(--gray-dark);
}

.quiz-progress-bar {
    height: 8px;
    background: var(--gray-light);
    border-radius: 4px;
    overflow: hidden;
}

.quiz-progress-fill {
    height: 100%;
    background: var(--gradient-primary);
    border-radius: 4px;
    transition: width var(--transition-normal);
}

.quiz-question {
    display: none;
}

.quiz-question.active {
    display: block;
    animation: fadeInUp 0.4s ease;
}

.question-text {
    font-size: 22px;
    font-weight: 700;
    text-align: center;
    margin-bottom: 32px;
    color: var(--dark);
}

.quiz-options {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.quiz-option {
    padding: 18px 24px;
    background: var(--light);
    border: 2px solid var(--gray-light);
    border-radius: var(--radius-md);
    font-family: var(--font-main);
    font-size: 16px;
    font-weight: 600;
    color: var(--dark);
    cursor: pointer;
    transition: all var(--transition-fast);
    text-align: left;
}

.quiz-option:hover:not(.selected) {
    border-color: var(--primary);
    background: rgba(108, 92, 231, 0.05);
}

.quiz-option.selected {
    pointer-events: none;
}

.quiz-option.correct {
    background: #D4EDDA;
    border-color: #28a745;
    color: #155724;
}

.quiz-option.wrong {
    background: #F8D7DA;
    border-color: var(--accent-orange);
    color: #721C24;
    animation: wrongShake 0.5s ease;
}

/* Результаты квиза */
.quiz-results {
    text-align: center;
    padding: 40px 20px;
}

.quiz-results.hidden {
    display: none;
}

.results-icon {
    font-size: 64px;
    margin-bottom: 16px;
}

.results-title {
    font-size: 28px;
    font-weight: 800;
    margin-bottom: 8px;
    color: var(--dark);
}

.results-text {
    font-size: 16px;
    color: var(--gray-dark);
    margin-bottom: 32px;
}

.score-circle {
    width: 120px;
    height: 120px;
    margin: 0 auto 32px;
    background: var(--accent-orange);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
}

.score-number {
    font-size: 36px;
    font-weight: 800;
}

.score-percent {
    font-size: 18px;
}

.results-actions {
    display: flex;
    gap: 16px;
    justify-content: center;
}

/* ========================================
   Игра
======================================== */

.game-container {
    padding: 20px 0;
}

.game-header {
    text-align: center;
    margin-bottom: 32px;
}

.game-header h2 {
    margin-bottom: 8px;
}

.game-header p {
    color: var(--gray-dark);
    margin-bottom: 16px;
}

.game-stats {
    display: flex;
    justify-content: center;
    gap: 24px;
    font-weight: 700;
}

.matching-game {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    max-width: 600px;
    margin: 0 auto;
}

.game-column {
    display: flex;
    flex-direction: column;
    gap: 12px;
}

.game-card {
    padding: 16px 24px;
    background: var(--light);
    border: 2px solid var(--gray-light);
    border-radius: var(--radius-md);
    font-size: 16px;
    font-weight: 600;
    text-align: center;
    cursor: pointer;
    transition: all var(--transition-fast);
}

.game-card:hover:not(.matched):not(.selected) {
    border-color: var(--primary);
    transform: scale(1.02);
}

.game-card.selected {
    border-color: var(--primary);
    background: rgba(108, 92, 231, 0.1);
    box-shadow: 0 0 0 3px rgba(108, 92, 231, 0.2);
}

.game-card.matched {
    background: #D4EDDA !important;
    border-color: #28a745 !important;
    color: #155724;
    pointer-events: none;
    animation: correctPop 0.5s ease;
}

.game-card.wrong {
    background: #F8D7DA !important;
    border-color: #DC3545 !important;
    color: #721c24;
    animation: wrongShake 0.5s ease;
}

.english-column .game-card {
    background: linear-gradient(135deg, #E8F4FD 0%, #D0E8F9 100%);
    border-color: #74B9FF;
}

.russian-column .game-card {
    background: linear-gradient(135deg, #FFF3E0 0%, #FFE0B2 100%);
    border-color: #FDCB6E;
}

/* Завершение игры */
.game-complete {
    text-align: center;
    padding: 40px 20px;
}

.game-complete.hidden {
    display: none;
}

.game-complete-icon {
    font-size: 64px;
    margin-bottom: 16px;
}

.game-complete h3 {
    font-size: 24px;
    margin-bottom: 8px;
}

.game-complete p {
    color: var(--gray-dark);
    margin-bottom: 24px;
}

/* ========================================
   Боковая панель
======================================== */

.lesson-sidebar {
    display: flex;
    flex-direction: column;
    gap: 24px;
    position: sticky;
    top: 80px;
}

.sidebar-card {
    background: var(--white);
    border-radius: var(--radius-lg);
    padding: 24px;
    box-shadow: var(--shadow-sm);
}

.sidebar-card h3 {
    font-size: 18px;
    font-weight: 700;
    margin-bottom: 16px;
}

/* Прогресс урока */
.progress-checklist {
    display: flex;
    flex-direction: column;
    gap: 12px;
    margin-bottom: 20px;
}

.progress-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px;
    background: var(--light);
    border-radius: var(--radius-sm);
    cursor: pointer;
    transition: background var(--transition-fast);
}

.progress-item:hover {
    background: var(--gray-light);
}

.progress-item input {
    display: none;
}

.progress-item .checkmark {
    width: 24px;
    height: 24px;
    border: 2px solid var(--gray);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    color: var(--white);
    transition: all var(--transition-fast);
    flex-shrink: 0;
}

.progress-item.completed .checkmark,
.progress-item input:checked + .checkmark {
    background: #4CAF50;
    border-color: #4CAF50;
}

.progress-item.completed .checkmark::after,
.progress-item input:checked + .checkmark::after {
    content: '✓';
    font-size: 14px;
    font-weight: bold;
}

.progress-item.completed span:last-child {
    color: #4CAF50;
    font-weight: 600;
}

.progress-item span:last-child {
    font-size: 14px;
    color: var(--dark);
}

.btn-block {
    width: 100%;
}

/* Навигация по урокам */
.lesson-nav-list {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.lesson-nav-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px;
    border-radius: var(--radius-sm);
    transition: background var(--transition-fast);
    text-decoration: none;
    color: inherit;
}

.lesson-nav-item:hover {
    background: var(--light);
}

.lesson-nav-item .nav-status {
    width: 24px;
    height: 24px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    flex-shrink: 0;
}

.lesson-nav-item.completed .nav-status {
    background: var(--accent-orange);
    color: var(--white);
}

.lesson-nav-item.current .nav-status {
    background: var(--primary);
    color: var(--white);
}

.lesson-nav-item.locked .nav-status {
    background: var(--gray-light);
}

.lesson-nav-item.current {
    background: rgba(108, 92, 231, 0.1);
}

.lesson-nav-item.locked {
    opacity: 0.6;
    cursor: not-allowed;
}

.nav-title {
    font-size: 13px;
    font-weight: 600;
}

/* Помощь */
.help-card {
    text-align: center;
    background: linear-gradient(135deg, #FFF9E6 0%, #FFF3CD 100%);
}

.help-icon {
    font-size: 48px;
    margin-bottom: 12px;
}

.help-card p {
    font-size: 14px;
    color: var(--gray-dark);
    margin-bottom: 16px;
}

/* ========================================
   Адаптивность
======================================== */

@media (max-width: 1024px) {
    .lesson-layout {
        grid-template-columns: 1fr;
    }
    
    .lesson-sidebar {
        position: static;
        display: grid;
        grid-template-columns: repeat(2, 1fr);
    }
    
    .lesson-nav-info {
        display: none;
    }
}

@media (max-width: 768px) {
    .lesson-navbar .nav-container {
        padding: 0 16px;
    }
    
    .back-text {
        display: none;
    }
    
    .lesson-nav-actions .btn {
        padding: 8px 12px;
        font-size: 13px;
    }
    
    .lesson-title {
        font-size: 24px;
    }
    
    .lesson-tabs {
        overflow-x: auto;
    }
    
    .tab-btn {
        padding: 14px 16px;
        font-size: 13px;
        white-space: nowrap;
    }
    
    .tab-content {
        padding: 20px;
    }
    
    .vocab-cards {
        grid-template-columns: 1fr;
    }
    
    .matching-game {
        grid-template-columns: 1fr;
        gap: 24px;
    }
    
    .lesson-sidebar {
        grid-template-columns: 1fr;
    }
    
    .results-actions {
        flex-direction: column;
    }
}