/* Individual Lecture Page Styles */

.breadcrumb {
    background: #f3f4f6;
    padding: 12px 20px;
    font-size: 14px;
}

.breadcrumb .container {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
}

.breadcrumb a {
    color: #6b7280;
    text-decoration: none;
    transition: color 0.3s;
}

.breadcrumb a:hover {
    color: #ff6b00;
}

.breadcrumb .separator {
    margin: 0 10px;
    color: #9ca3af;
}

.breadcrumb span:last-child {
    color: #1f2937;
    font-weight: 500;
}

.lecture-header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 60px 20px;
}

.lecture-header-content h1 {
    font-size: 42px;
    margin: 20px 0 15px 0;
}

.lecture-subtitle {
    font-size: 20px;
    opacity: 0.9;
    margin-bottom: 30px;
}

.lecture-info {
    display: flex;
    flex-wrap: wrap;
    gap: 25px;
}

.info-item {
    display: flex;
    align-items: center;
    gap: 8px;
}

.info-item i {
    font-size: 16px;
}

.lecture-content-section {
    padding: 60px 20px;
    background: #f9fafb;
}

.lecture-layout {
    display: grid;
    grid-template-columns: 1fr 350px;
    gap: 40px;
    max-width: 1400px;
    margin: 0 auto;
}

.lecture-main {
    background: white;
    border-radius: 12px;
    padding: 40px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.content-block {
    margin-bottom: 50px;
}

.content-block:last-child {
    margin-bottom: 0;
}

.content-block h2 {
    color: #1f2937;
    font-size: 28px;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 3px solid #ff6b00;
}

.content-block p {
    line-height: 1.8;
    color: #4b5563;
    margin-bottom: 15px;
}

/* Tone Cards */
.tone-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 20px;
    margin: 30px 0;
}

.tone-card {
    background: #f9fafb;
    border: 2px solid #e5e7eb;
    border-radius: 12px;
    padding: 25px;
    text-align: center;
    transition: all 0.3s ease;
    position: relative;
}

.tone-card:hover {
    border-color: #ff6b00;
    transform: translateY(-5px);
    box-shadow: 0 8px 16px rgba(255, 107, 0, 0.2);
}

.tone-number {
    position: absolute;
    top: 15px;
    right: 15px;
    background: #ff6b00;
    color: white;
    width: 35px;
    height: 35px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
}

.tone-card h3 {
    font-size: 18px;
    color: #1f2937;
    margin-bottom: 10px;
}

.tone-symbol {
    font-size: 36px;
    color: #ff6b00;
    margin: 10px 0;
}

.tone-vietnamese {
    font-size: 32px;
    font-weight: 700;
    color: #2c3e50;
    margin: 10px 0 5px 0;
}

.tone-meaning {
    color: #6b7280;
    font-size: 16px;
    margin-bottom: 15px;
}

.play-tone-btn {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    border: none;
    padding: 10px 20px;
    border-radius: 8px;
    cursor: pointer;
    font-weight: 600;
    margin: 15px 0;
    transition: transform 0.2s;
}

.play-tone-btn:hover {
    transform: scale(1.05);
}

.tone-description {
    font-size: 14px;
    color: #6b7280;
    line-height: 1.6;
    margin-top: 15px;
}

/* Tips List */
.tips-list {
    list-style: none;
    padding: 0;
}

.tips-list li {
    padding: 15px 20px;
    margin-bottom: 15px;
    background: #f0f9ff;
    border-left: 4px solid #0ea5e9;
    border-radius: 8px;
    line-height: 1.6;
}

.tips-list li strong {
    color: #0369a1;
}

/* Exercise Boxes */
.exercise-box {
    background: #fef3c7;
    border: 2px solid #fbbf24;
    border-radius: 12px;
    padding: 25px;
    margin: 20px 0;
}

.exercise-box h3 {
    color: #92400e;
    margin-bottom: 15px;
}

.minimal-pairs {
    display: flex;
    justify-content: center;
    margin: 20px 0;
}

.pair-row {
    display: flex;
    gap: 15px;
    flex-wrap: wrap;
}

.pair-row .word {
    font-size: 24px;
    font-weight: 700;
    color: #1f2937;
    padding: 10px 20px;
    background: white;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}

.btn-practice {
    background: #8b5cf6;
    color: white;
    border: none;
    padding: 12px 24px;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
}

.btn-practice:hover {
    background: #7c3aed;
    transform: translateY(-2px);
}

/* CTA Block */
.cta-block {
    background: linear-gradient(135deg, #f093fb 0%, #f5576c 100%);
    color: white;
    padding: 40px;
    border-radius: 12px;
    text-align: center;
}

.cta-block h2 {
    color: white;
    border: none;
}

.cta-block p {
    color: white;
    opacity: 0.9;
}

.btn-cta {
    display: inline-flex;
    align-items: center;
    gap: 10px;
    background: white;
    color: #f5576c;
    padding: 15px 30px;
    border-radius: 10px;
    text-decoration: none;
    font-weight: 600;
    margin-top: 20px;
    transition: all 0.3s;
}

.btn-cta:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 16px rgba(0,0,0,0.2);
}

/* Lecture Navigation */
.lecture-navigation {
    display: flex;
    justify-content: space-between;
    margin-top: 50px;
    padding-top: 30px;
    border-top: 2px solid #e5e7eb;
}

.nav-btn {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 15px 25px;
    background: #f3f4f6;
    color: #1f2937;
    text-decoration: none;
    border-radius: 8px;
    font-weight: 600;
    transition: all 0.3s;
}

.nav-btn:hover {
    background: #ff6b00;
    color: white;
}

.nav-btn.prev[disabled] {
    opacity: 0.5;
    cursor: not-allowed;
}

.nav-btn.prev[disabled]:hover {
    background: #f3f4f6;
    color: #1f2937;
}

/* Sidebar */
.lecture-sidebar {
    display: flex;
    flex-direction: column;
    gap: 25px;
}

.sidebar-card {
    background: white;
    border-radius: 12px;
    padding: 25px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
}

.sidebar-card h3 {
    font-size: 18px;
    margin-bottom: 20px;
    color: #1f2937;
}

.progress-circle {
    width: 120px;
    height: 120px;
    border-radius: 50%;
    background: conic-gradient(#10b981 0%, #e5e7eb 0%);
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 20px auto;
    position: relative;
}

.progress-circle::before {
    content: '';
    position: absolute;
    width: 90px;
    height: 90px;
    background: white;
    border-radius: 50%;
}

.progress-percent {
    position: relative;
    z-index: 1;
    font-size: 24px;
    font-weight: 700;
    color: #1f2937;
}

.btn-complete {
    width: 100%;
    padding: 12px;
    background: #ff6b00;
    color: white;
    border: none;
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s;
}

.btn-complete:hover {
    background: #e55d00;
}

.related-list {
    list-style: none;
    padding: 0;
}

.related-list li {
    margin-bottom: 12px;
}

.related-list a {
    color: #4b5563;
    text-decoration: none;
    display: block;
    padding: 10px;
    border-radius: 6px;
    transition: all 0.3s;
}

.related-list a:hover {
    background: #f3f4f6;
    color: #ff6b00;
}

.quick-link {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px;
    color: #4b5563;
    text-decoration: none;
    border-radius: 8px;
    margin-bottom: 10px;
    transition: all 0.3s;
}

.quick-link:hover {
    background: #f3f4f6;
    color: #ff6b00;
}

.quick-link i {
    font-size: 18px;
}

/* Responsive */
@media (max-width: 968px) {
    .lecture-layout {
        grid-template-columns: 1fr;
    }
    
    .lecture-sidebar {
        order: -1;
    }
    
    .lecture-header-content h1 {
        font-size: 32px;
    }
    
    .lecture-info {
        flex-direction: column;
        gap: 10px;
    }
    
    .tone-cards {
        grid-template-columns: 1fr;
    }
}

/* Filter Section Styles (for lectures list page) */
.filter-section {
    background: white;
    padding: 30px 20px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.05);
}

.filter-controls {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
    align-items: end;
}

.filter-group {
    flex: 1;
    min-width: 200px;
}

.filter-group label {
    display: block;
    font-weight: 600;
    margin-bottom: 8px;
    color: #374151;
}

.filter-select {
    width: 100%;
    padding: 10px 15px;
    border: 2px solid #d1d5db;
    border-radius: 8px;
    font-size: 15px;
    cursor: pointer;
    background: white;
    transition: all 0.3s;
}

.filter-select:focus {
    outline: none;
    border-color: #ff6b00;
}

/* Lectures Grid (for list page) */
.lectures-section {
    padding: 60px 20px;
    background: #f9fafb;
}

.lectures-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(350px, 1fr));
    gap: 30px;
    margin-bottom: 40px;
}

.lecture-card {
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0,0,0,0.1);
    transition: all 0.3s;
}

.lecture-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 24px rgba(0,0,0,0.15);
}

.lecture-image {
    position: relative;
    height: 200px;
    overflow: hidden;
}

.lecture-image img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.3s;
}

.lecture-card:hover .lecture-image img {
    transform: scale(1.1);
}

.lecture-badge {
    position: absolute;
    top: 15px;
    right: 15px;
    padding: 6px 12px;
    border-radius: 6px;
    font-weight: 600;
    font-size: 12px;
}

.beginner-badge {
    background: #d1fae5;
    color: #065f46;
}

.intermediate-badge {
    background: #fef3c7;
    color: #92400e;
}

.advanced-badge {
    background: #fee2e2;
    color: #991b1b;
}

.lecture-content {
    padding: 25px;
}

.lecture-meta {
    display: flex;
    justify-content: space-between;
    font-size: 13px;
    color: #6b7280;
    margin-bottom: 15px;
}

.lecture-topic {
    display: flex;
    align-items: center;
    gap: 5px;
}

.lecture-title {
    font-size: 20px;
    margin-bottom: 12px;
}

.lecture-title a {
    color: #1f2937;
    text-decoration: none;
    transition: color 0.3s;
}

.lecture-title a:hover {
    color: #ff6b00;
}

.lecture-description {
    color: #6b7280;
    line-height: 1.6;
    margin-bottom: 20px;
}

.lecture-stats {
    display: flex;
    gap: 20px;
    font-size: 14px;
    color: #6b7280;
    margin-bottom: 20px;
    padding-top: 20px;
    border-top: 1px solid #e5e7eb;
}

.lecture-stats span {
    display: flex;
    align-items: center;
    gap: 6px;
}

.lecture-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: #ff6b00;
    text-decoration: none;
    font-weight: 600;
    transition: gap 0.3s;
}

.lecture-link:hover {
    gap: 12px;
}

/* Load More Button */
.load-more-container {
    text-align: center;
    margin-top: 40px;
}

.btn-load-more {
    padding: 15px 40px;
    background: white;
    border: 2px solid #e5e7eb;
    border-radius: 10px;
    font-weight: 600;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 10px;
    transition: all 0.3s;
}

.btn-load-more:hover {
    border-color: #ff6b00;
    color: #ff6b00;
    transform: translateY(-2px);
}

/* CTA Section */
.cta-section {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 80px 20px;
    text-align: center;
    color: white;
}

.cta-content h2 {
    font-size: 36px;
    margin-bottom: 15px;
}

.cta-content p {
    font-size: 18px;
    opacity: 0.9;
    margin-bottom: 30px;
}