/* 重置和基本样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: 'Segoe UI', 'Microsoft YaHei', sans-serif;
}

body {
    background: linear-gradient(135deg, #f7f9fc 0%, #eef2f7 100%);
    color: #333;
    line-height: 1.6;
    padding: 20px;
}

.course-container {
    max-width: 1200px;
    margin: 30px auto;
    background: white;
    border-radius: 15px;
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.08);
    overflow: hidden;
}

.content-header {
    padding: 30px 40px;
    background: linear-gradient(90deg, #4b6cb7 0%, #182848 100%);
    color: white;
}

.content-header h1 {
    font-size: 2.5rem;
    margin-bottom: 15px;
    text-shadow: 2px 2px 4px rgba(0, 0, 0, 0.3);
    display: flex;
    align-items: center;
    gap: 15px;
}

.scratch-icon {
    width: 60px;
    height: 60px;
    background: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    box-shadow: 0 0 20px rgba(255, 255, 255, 0.3);
}

.scratch-icon i {
    font-size: 2.5rem;
    color: #ff6b35;
}

.course-overview {
    padding: 30px 40px;
    background: white;
}

.section-title {
    font-size: 2.0rem;
    margin: 40px 0 20px;
    color: #2c3e50;
    position: relative;
    padding-bottom: 10px;
    border-bottom: 2px solid #e6e9ff;
}

.section-title::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 80px;
    height: 4px;
    background: #4b6cb7;
    border-radius: 2px;
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
    margin: 30px 0;
    padding: 0 20px;
}

.feature-card {
    background: #f8f9ff;
    border-radius: 10px;
    padding: 25px;
    border-left: 4px solid #4b6cb7;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
    transition: all 0.3s ease;
}

.feature-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.1);
}

.feature-card h3 {
    font-size: 1.3rem;
    margin-bottom: 15px;
    color: #2c3e50;
    display: flex;
    align-items: center;
    gap: 10px;
}

.level-section {
    margin: 40px 0;
    padding: 25px;
    background: #f8f9ff;
    border-radius: 12px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
}

.level-title {
    font-size: 1.8rem;
    margin-bottom: 25px;
    color: #2c3e50;
    display: flex;
    align-items: center;
    gap: 15px;
    padding-bottom: 10px;
    border-bottom: 2px solid #e6e9ff;
}

.level-content {
    margin-left: 15px;
}

.level-content h4 {
    font-size: 1.2rem;
    margin: 20px 0 10px;
    color: #3a506b;
}

.level-content ul {
    padding-left: 25px;
    margin-bottom: 20px;
}

.level-content li {
    margin-bottom: 10px;
    position: relative;
    padding-left: 15px;
}

.level-content li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: #ff6b35;
    font-weight: bold;
}

.curriculum-table {
    width: 100%;
    border-collapse: collapse;
    margin: 25px 0;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
    border-radius: 10px;
    overflow: hidden;
}

.curriculum-table th {
    background: #4b6cb7;
    color: white;
    padding: 15px;
    text-align: left;
    font-weight: 600;
}

.curriculum-table td {
    padding: 15px;
    border-bottom: 1px solid #e6e9ff;
    vertical-align: top;
}

.curriculum-table tr:nth-child(even) {
    background: #f8f9ff;
}

.curriculum-table tr:last-child td {
    border-bottom: none;
}

.curriculum-table tr:hover {
    background: #edf0ff;
}

/* 调整表格列宽 */
.curriculum-table th:nth-child(1),
.curriculum-table td:nth-child(1) {
    width: 8%;
}

.curriculum-table th:nth-child(2),
.curriculum-table td:nth-child(2) {
    width: 20%;
    white-space: nowrap;
}

.curriculum-table th:nth-child(3),
.curriculum-table td:nth-child(3) {
    width: 72%;
}

.image-container {
    display: flex;
    justify-content: center;
    gap: 25px;
    margin: 30px 0;
    padding: 0 20px;
    flex-wrap: wrap;
}

.image-wrapper {
    flex: 1;
    min-width: 300px;
    max-width: 100%;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
    border-radius: 10px;
    overflow: hidden;
    transition: all 0.3s ease;
    display: flex;
    flex-direction: column;
    align-items: center;
    padding: 15px;
    background: #f8f9ff;
}

.image-wrapper:hover {
    transform: translateY(-5px);
    box-shadow: 0 10px 25px rgba(0, 0, 0, 0.15);
}

.image-wrapper img {
    width: 100%;
    height: auto;
    display: block;
    object-fit: cover;
    border-radius: 8px;
}

.image-caption {
    padding: 15px 0 5px;
    text-align: center;
    font-weight: 500;
    color: #3a506b;
    width: 100%;
}

.teacher-section {
    margin: 40px 0;
    padding: 30px;
    background: #f8f9ff;
    border-radius: 12px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.05);
}

.manual-title {
    font-size: 1.8rem;
    margin-bottom: 25px;
    color: #2c3e50;
    padding-bottom: 10px;
    border-bottom: 2px solid #e6e9ff;
    position: relative;
}

.manual-title::after {
    content: '';
    position: absolute;
    bottom: -2px;
    left: 0;
    width: 80px;
    height: 4px;
    background: #4b6cb7;
    border-radius: 2px;
}

.manual-section {
    margin: 30px 0;
}

.manual-subtitle {
    font-size: 1.4rem;
    color: #3a506b;
    margin: 20px 0 15px;
    padding-bottom: 8px;
    border-bottom: 1px solid #e6e9ff;
}

.manual-content {
    margin-left: 15px;
    line-height: 1.7;
}

.manual-content p {
    margin-bottom: 15px;
}

.manual-images {
    display: flex;
    flex-wrap: wrap;
    gap: 15px;
    margin: 15px 0;
}

.manual-img {
    max-width: 100%;
    max-height: 200px;
    border-radius: 8px;
    box-shadow: 0 5px 15px rgba(0, 0, 0, 0.1);
}

.manual-list {
    padding-left: 25px;
    margin: 15px 0;
}

.manual-list li {
    margin-bottom: 10px;
    position: relative;
    padding-left: 15px;
}

.manual-list li::before {
    content: '•';
    position: absolute;
    left: 0;
    color: #ff6b35;
    font-weight: bold;
}

.manual-question {
    background: #edf2ff;
    padding: 15px;
    border-radius: 8px;
    margin: 20px 0;
    border-left: 3px solid #4b6cb7;
}

.module-comparison {
    display: flex;
    gap: 20px;
    margin: 20px 0;
    flex-wrap: wrap;
}

.module-card {
    flex: 1;
    min-width: 200px;
    background: #f0f5ff;
    padding: 15px;
    border-radius: 8px;
    text-align: center;
}

.course-footer {
    text-align: center;
    padding: 30px;
    background: #2c3e50;
    color: white;
    border-top: 1px solid rgba(255, 255, 255, 0.1);
}

.course-footer p {
    margin: 10px 0;
}

.course-footer img {
    max-width: 100%;
    margin-top: 20px;
    border-radius: 8px;
}

@media (max-width: 768px) {
    .content-header h1 {
        font-size: 2.0rem;
    }
    
    .section-title {
        font-size: 1.7rem;
    }
    
    .curriculum-table {
        display: block;
        overflow-x: auto;
    }
    
    .curriculum-table th:nth-child(2),
    .curriculum-table td:nth-child(2) {
        white-space: normal;
    }
    
    .teacher-content {
        flex-direction: column;
    }
    
    .manual-images {
        flex-direction: column;
    }
    
    .image-container {
        flex-direction: column;
    }
    
    .features {
        grid-template-columns: 1fr;
    }
}