/* Teaching Resources Section Styles */

.resources {
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    padding: 80px 0;
}

.resources-section {
    margin-bottom: 60px;
}

.resources-section h3 {
    font-size: 2rem;
    color: #2c3e50;
    margin-bottom: 30px;
    text-align: center;
    position: relative;
}

.resources-section h3::after {
    content: '';
    position: absolute;
    bottom: -10px;
    left: 50%;
    transform: translateX(-50%);
    width: 60px;
    height: 3px;
    background: linear-gradient(90deg, #3498db, #2980b9);
    border-radius: 2px;
}

/* Learning Paths */
.learning-paths-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-bottom: 40px;
}

.path-card {
    background: white;
    border-radius: 15px;
    padding: 25px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    border: 2px solid transparent;
}

.path-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
    border-color: #3498db;
}

.path-header {
    display: flex;
    align-items: center;
    margin-bottom: 20px;
    padding-bottom: 15px;
    border-bottom: 2px solid #ecf0f1;
}

.path-header i {
    font-size: 2rem;
    margin-right: 15px;
    color: #3498db;
}

.path-header h4 {
    font-size: 1.3rem;
    color: #2c3e50;
    margin: 0;
}

.path-content {
    margin-bottom: 20px;
}

.path-step {
    display: flex;
    align-items: center;
    margin-bottom: 12px;
    padding: 8px 0;
}

.step-number {
    background: linear-gradient(135deg, #3498db, #2980b9);
    color: white;
    width: 28px;
    height: 28px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: bold;
    font-size: 0.9rem;
    margin-right: 15px;
    flex-shrink: 0;
}

.path-step span:last-child {
    color: #34495e;
    font-size: 0.95rem;
}

.path-duration {
    display: flex;
    align-items: center;
    color: #7f8c8d;
    font-size: 0.9rem;
    padding-top: 15px;
    border-top: 1px solid #ecf0f1;
}

.path-duration i {
    margin-right: 8px;
    color: #f39c12;
}

/* Free Resources */
.resources-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
    gap: 25px;
    margin-bottom: 40px;
}

.resource-card {
    background: white;
    border-radius: 12px;
    padding: 25px;
    text-align: center;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    border: 1px solid #e9ecef;
}

.resource-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.12);
    border-color: #3498db;
}

.resource-icon {
    width: 70px;
    height: 70px;
    background: linear-gradient(135deg, #3498db, #2980b9);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
}

.resource-icon i {
    font-size: 2rem;
    color: white;
}

.resource-card h4 {
    color: #2c3e50;
    margin-bottom: 12px;
    font-size: 1.1rem;
}

.resource-card p {
    color: #7f8c8d;
    font-size: 0.9rem;
    line-height: 1.5;
    margin-bottom: 20px;
}

.resource-meta {
    display: flex;
    justify-content: center;
    gap: 15px;
    margin-bottom: 20px;
}

.resource-type, .resource-size {
    background: #f8f9fa;
    color: #6c757d;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
}

.btn-small {
    padding: 8px 20px;
    font-size: 0.9rem;
    background: linear-gradient(135deg, #27ae60, #2ecc71);
    color: white;
    border: none;
    border-radius: 25px;
    text-decoration: none;
    display: inline-block;
    transition: all 0.3s ease;
}

.btn-small:hover {
    transform: translateY(-2px);
    box-shadow: 0 5px 15px rgba(39, 174, 96, 0.3);
    color: white;
}

/* Study Materials */
.materials-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 25px;
    margin-bottom: 40px;
}

.material-card {
    background: white;
    border-radius: 12px;
    padding: 25px;
    display: flex;
    align-items: center;
    box-shadow: 0 8px 25px rgba(0, 0, 0, 0.08);
    transition: all 0.3s ease;
    border: 1px solid #e9ecef;
}

.material-card:hover {
    transform: translateY(-3px);
    box-shadow: 0 15px 35px rgba(0, 0, 0, 0.12);
    border-color: #3498db;
}

.material-cover {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, #e74c3c, #c0392b);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-right: 20px;
    flex-shrink: 0;
}

.material-cover i {
    font-size: 2.5rem;
    color: white;
}

.material-info {
    flex: 1;
}

.material-info h4 {
    color: #2c3e50;
    margin-bottom: 8px;
    font-size: 1.1rem;
}

.material-info p {
    color: #7f8c8d;
    font-size: 0.9rem;
    margin-bottom: 8px;
    line-height: 1.4;
}

.material-info p:first-of-type {
    color: #e74c3c;
    font-weight: 500;
}

.material-tags {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}

.tag {
    display: inline-block;
    background: var(--light);
    color: var(--primary);
    padding: 0.3rem 0.8rem;
    border-radius: 15px;
    font-size: 0.8rem;
    font-weight: 500;
    margin-right: 0.5rem;
    margin-bottom: 0.5rem;
}

.tag-link {
    text-decoration: none;
    transition: all 0.3s ease;
    cursor: pointer;
}

.tag-link:hover {
    background: var(--primary);
    color: white;
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(37, 99, 235, 0.3);
}

/* Resource CTA */
.resources-cta {
    background: linear-gradient(135deg, #2c3e50, #34495e);
    border-radius: 15px;
    padding: 40px;
    text-align: center;
    color: white;
}

.cta-content h3 {
    font-size: 1.8rem;
    margin-bottom: 15px;
    color: white;
}

.cta-content h3::after {
    display: none;
}

.cta-content p {
    font-size: 1.1rem;
    margin-bottom: 25px;
    opacity: 0.9;
    line-height: 1.6;
}

/* Responsive Design */
@media (max-width: 768px) {
    .page-header {
        margin-top: 60px; /* 移动端导航栏高度较小 */
        padding: 60px 0 40px;
    }
    
    .learning-paths-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .resources-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .materials-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .material-card {
        flex-direction: column;
        text-align: center;
    }
    
    .material-cover {
        margin-right: 0;
        margin-bottom: 20px;
    }
    
    .resources-cta {
        padding: 30px 20px;
    }
    
    .cta-content h3 {
        font-size: 1.5rem;
    }
    
    /* Preview section responsive */
    .preview-grid {
        grid-template-columns: 1fr;
        gap: 20px;
    }
    
    .preview-card {
        padding: 25px;
    }
    
    .header-content h1 {
        font-size: 2rem;
    }
    
    .header-content p {
        font-size: 1.1rem;
    }
    
    .cta-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .btn-outline, .preview-cta .btn {
        width: 100%;
        max-width: 300px;
        text-align: center;
    }
}

@media (max-width: 480px) {
    .page-header {
        margin-top: 50px; /* 小屏幕设备导航栏高度更小 */
        padding: 50px 0 30px;
    }
    
    .path-card, .resource-card, .material-card {
        padding: 20px;
    }
    
    .path-header h4 {
        font-size: 1.1rem;
    }
    
    .resource-icon {
        width: 60px;
        height: 60px;
    }
    
    .resource-icon i {
        font-size: 1.5rem;
    }
}

/* Resources Preview Section Styles */
.resources-preview {
    background: linear-gradient(135deg, #f8f9fa 0%, #e9ecef 100%);
    padding: 80px 0;
}

.resources-preview-content {
    text-align: center;
}

.preview-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 30px;
    margin-bottom: 40px;
}

.preview-card {
    background: white;
    border-radius: 15px;
    padding: 30px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    border: 2px solid transparent;
    position: relative;
    overflow: hidden;
}

.preview-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, #3498db, #2980b9);
    transform: scaleX(0);
    transition: transform 0.3s ease;
}

.preview-card:hover::before {
    transform: scaleX(1);
}

.preview-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 20px 40px rgba(0, 0, 0, 0.15);
    border-color: #3498db;
}

.preview-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, #3498db, #2980b9);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 20px;
    transition: all 0.3s ease;
}

.preview-card:hover .preview-icon {
    transform: scale(1.1);
    box-shadow: 0 10px 20px rgba(52, 152, 219, 0.3);
}

.preview-icon i {
    font-size: 2.5rem;
    color: white;
}

.preview-card h3 {
    color: #2c3e50;
    margin-bottom: 15px;
    font-size: 1.3rem;
    font-weight: 600;
}

.preview-card p {
    color: #7f8c8d;
    font-size: 0.95rem;
    line-height: 1.6;
    margin: 0;
}

.preview-cta {
    margin-top: 20px;
}

.preview-cta .btn {
    padding: 15px 30px;
    font-size: 1.1rem;
    background: linear-gradient(135deg, #2563eb, #1d4ed8);
    border: none;
    border-radius: 30px;
    color: white;
    text-decoration: none;
    display: inline-block;
    transition: all 0.3s ease;
    box-shadow: 0 5px 15px rgba(37, 99, 235, 0.3);
}

.preview-cta .btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(37, 99, 235, 0.4);
    color: white;
}

/* Page Header Styles */
.page-header {
    background: linear-gradient(135deg, #2c3e50, #34495e);
    color: white;
    padding: 80px 0 60px;
    text-align: center;
    margin-top: 70px; /* 为固定导航栏留出空间 */
}

.header-content h1 {
    font-size: 2.5rem;
    margin-bottom: 15px;
    color: white;
}

.header-content p {
    font-size: 1.2rem;
    margin-bottom: 25px;
    opacity: 0.9;
    line-height: 1.6;
}



/* Enhanced Path Card Styles */
.path-card.featured {
    position: relative;
    border-color: #f39c12;
    transform: scale(1.05);
}

.path-badge {
    position: absolute;
    top: -10px;
    right: 20px;
    background: linear-gradient(135deg, #f39c12, #e67e22);
    color: white;
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: bold;
    box-shadow: 0 3px 10px rgba(243, 156, 18, 0.3);
}

.path-suitable {
    display: flex;
    align-items: center;
    color: #7f8c8d;
    font-size: 0.85rem;
    padding-top: 10px;
    border-top: 1px solid #ecf0f1;
    margin-top: 15px;
}

.path-suitable i {
    margin-right: 8px;
    color: #3498db;
}

/* Enhanced Resource Card Styles */
.resource-downloads {
    background: #e8f5e8;
    color: #27ae60;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 0.8rem;
    font-weight: 500;
}

/* Enhanced Material Card Styles */
.material-rating {
    display: flex;
    align-items: center;
    gap: 10px;
    margin-top: 15px;
}

.stars {
    display: flex;
    gap: 2px;
}

.stars i {
    color: #f39c12;
    font-size: 0.9rem;
}

.material-rating span {
    color: #7f8c8d;
    font-size: 0.8rem;
}

/* Enhanced CTA Styles */
.cta-buttons {
    display: flex;
    gap: 15px;
    justify-content: center;
    flex-wrap: wrap;
}

.btn-outline {
    background: transparent;
    border: 2px solid white;
    color: white;
    padding: 15px 30px;
    font-size: 1.1rem;
    border-radius: 30px;
    text-decoration: none;
    display: inline-block;
    transition: all 0.3s ease;
}

.btn-outline:hover {
    background: white;
    color: #2c3e50;
    transform: translateY(-2px);
}



@media (max-width: 480px) {
    .preview-card {
        padding: 20px;
    }
    
    .preview-icon {
        width: 60px;
        height: 60px;
    }
    
    .preview-icon i {
        font-size: 2rem;
    }
    
    .preview-card h3 {
        font-size: 1.1rem;
    }
    
    .header-content h1 {
        font-size: 1.8rem;
    }
}