* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Noto Serif SC', 'SimSun', serif;
    background: linear-gradient(135deg, #f5f0e8 0%, #e8e0d5 100%);
    color: #3d3d3d;
    line-height: 1.8;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
}

header {
    text-align: center;
    padding: 40px 20px;
    background: linear-gradient(135deg, #8b4513 0%, #654321 100%);
    color: #f5f0e8;
    border-radius: 0 0 30px 30px;
    margin-bottom: 30px;
}

header h1 {
    font-size: 2.5em;
    margin-bottom: 10px;
}

header p {
    font-size: 1.1em;
    opacity: 0.9;
}

nav {
    background: white;
    padding: 15px;
    border-radius: 15px;
    margin-bottom: 40px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
}

nav ul {
    list-style: none;
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 20px;
}

nav a {
    color: #8b4513;
    text-decoration: none;
    padding: 10px 20px;
    border-radius: 25px;
    transition: all 0.3s;
}

nav a:hover {
    background: #f0e6d3;
}

.back-link {
    display: inline-block;
    margin-bottom: 20px;
    color: #8b4513;
    text-decoration: none;
    padding: 10px 20px;
    background: white;
    border-radius: 25px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    transition: all 0.3s;
}

.back-link:hover {
    background: #f0e6d3;
}

.card-link {
    text-decoration: none;
    color: inherit;
    display: block;
}

.section-subtitle {
    text-align: center;
    color: #888;
    margin: 30px 0;
}

.stats {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
    margin-bottom: 40px;
}

.stat-card {
    background: white;
    padding: 30px;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
    border-top: 4px solid #8b4513;
    transition: transform 0.3s;
}

.stat-card:hover {
    transform: translateY(-5px);
}

.stat-card h3 {
    font-size: 2.5em;
    color: #8b4513;
    margin-bottom: 10px;
}

.stat-card p {
    color: #666;
}

.section-title {
    font-size: 2em;
    color: #8b4513;
    margin: 50px 0 30px;
    text-align: center;
    border-bottom: 2px solid #d4c4b0;
    padding-bottom: 15px;
}

.classics-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 25px;
    margin-bottom: 40px;
}

.classic-card {
    background: white;
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
    transition: all 0.3s;
    border-left: 5px solid #8b4513;
}

.classic-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 15px 40px rgba(0,0,0,0.2);
}

.classic-card h3 {
    color: #8b4513;
    font-size: 1.5em;
    margin-bottom: 10px;
}

.classic-card .school {
    display: inline-block;
    padding: 5px 15px;
    background: #f0e6d3;
    border-radius: 20px;
    font-size: 0.9em;
    color: #8b4513;
    margin-bottom: 15px;
}

.classic-card p {
    color: #666;
    margin-bottom: 15px;
}

.classic-card .concepts {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
    margin-bottom: 15px;
}

.classic-card .concept-tag {
    padding: 3px 10px;
    background: #e8e0d5;
    border-radius: 15px;
    font-size: 0.85em;
    color: #5d4e37;
}

.classic-card .resources {
    font-size: 0.9em;
    color: #888;
    border-top: 1px solid #eee;
    padding-top: 10px;
    margin-top: 10px;
}

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 25px;
}

.course-card {
    background: white;
    padding: 30px;
    border-radius: 15px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
    transition: all 0.3s;
}

.course-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 15px 40px rgba(0,0,0,0.15);
}

.course-icon {
    font-size: 3em;
    margin-bottom: 15px;
}

.course-card h3 {
    color: #8b4513;
    font-size: 1.4em;
    margin-bottom: 10px;
}

.course-meta {
    display: flex;
    gap: 15px;
    margin-bottom: 15px;
    font-size: 0.9em;
    color: #666;
    flex-wrap: wrap;
}

.course-meta span {
    background: #f5f0e8;
    padding: 5px 12px;
    border-radius: 15px;
}

.features {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 25px;
    margin-bottom: 40px;
}

.feature-card {
    background: white;
    padding: 30px;
    border-radius: 15px;
    text-align: center;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
    transition: transform 0.3s;
}

.feature-card:hover {
    transform: translateY(-5px);
}

.feature-card .icon {
    font-size: 3em;
    margin-bottom: 15px;
}

.feature-card h3 {
    color: #8b4513;
    margin-bottom: 10px;
}

.chapter {
    background: white;
    padding: 30px;
    border-radius: 15px;
    margin-bottom: 20px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
}

.chapter h2 {
    color: #8b4513;
    font-size: 1.5em;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid #d4c4b0;
}

.original {
    font-size: 1.2em;
    color: #333;
    margin-bottom: 20px;
    padding: 20px;
    background: #f9f7f4;
    border-radius: 10px;
    border-left: 4px solid #8b4513;
}

.translation {
    color: #555;
    margin-bottom: 15px;
}

.commentary {
    background: #f5f0e8;
    padding: 15px;
    border-radius: 10px;
    margin-top: 15px;
}

.commentary h4 {
    color: #8b4513;
    margin-bottom: 10px;
}

.course-info {
    background: white;
    padding: 30px;
    border-radius: 15px;
    margin-bottom: 20px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
}

.meta-tag {
    background: #f0e6d3;
    padding: 5px 15px;
    border-radius: 20px;
    font-size: 0.9em;
    color: #8b4513;
}

.phase {
    background: white;
    padding: 25px;
    border-radius: 15px;
    margin-bottom: 15px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
    border-left: 4px solid #8b4513;
}

.phase h3 {
    color: #8b4513;
    margin-bottom: 10px;
}

.phase-meta {
    color: #888;
    font-size: 0.9em;
    margin-bottom: 10px;
}

.start-btn {
    display: block;
    width: 100%;
    padding: 15px;
    background: linear-gradient(135deg, #8b4513 0%, #654321 100%);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 1.2em;
    cursor: pointer;
    margin-top: 20px;
    text-align: center;
    text-decoration: none;
    transition: opacity 0.3s;
}

.start-btn:hover {
    opacity: 0.9;
}

.concept-section {
    background: white;
    padding: 30px;
    border-radius: 15px;
    margin-bottom: 20px;
    box-shadow: 0 5px 20px rgba(0,0,0,0.1);
}

.concept-section h2 {
    color: #8b4513;
    font-size: 1.5em;
    margin-bottom: 20px;
    padding-bottom: 10px;
    border-bottom: 2px solid #d4c4b0;
}

.concept-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 15px;
}

.concept-card {
    background: #f9f7f4;
    padding: 20px;
    border-radius: 10px;
    border-left: 4px solid #8b4513;
}

.concept-card h3 {
    color: #8b4513;
    margin-bottom: 8px;
}

.concept-card p {
    font-size: 0.9em;
    color: #666;
}

footer {
    text-align: center;
    padding: 30px 40px;
    background: #3d3d3d;
    color: #f5f0e8;
    border-radius: 30px 30px 0 0;
    margin-top: 40px;
}

footer p {
    opacity: 0.8;
}

@media (max-width: 768px) {
    header h1 {
        font-size: 2em;
    }
    .classics-grid,
    .courses-grid {
        grid-template-columns: 1fr;
    }
    nav ul {
        gap: 10px;
    }
    nav a {
        padding: 8px 15px;
        font-size: 0.9em;
    }
}