/* 基础样式重置 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f8fafc;
}

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

/* 导航栏 */
.navbar {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    padding: 1rem 0;
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

.nav-container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.nav-logo {
    display: flex;
    align-items: center;
    color: white;
    font-size: 1.5rem;
    font-weight: 600;
}

.nav-logo i {
    margin-right: 10px;
    font-size: 1.8rem;
}

.nav-menu {
    display: flex;
    gap: 2rem;
}

.nav-link {
    color: white;
    text-decoration: none;
    font-weight: 500;
    transition: opacity 0.3s ease;
}

.nav-link:hover {
    opacity: 0.8;
}

/* 英雄区域 */
.hero {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 120px 0 80px;
    text-align: center;
}

.hero-container {
    max-width: 800px;
    margin: 0 auto;
    padding: 0 20px;
}

.hero-title {
    font-size: 3.5rem;
    font-weight: 700;
    margin-bottom: 1.5rem;
    background: linear-gradient(45deg, #fff, #f0f0f0);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}

.hero-subtitle {
    font-size: 1.25rem;
    margin-bottom: 2rem;
    opacity: 0.9;
    line-height: 1.8;
}

.hero-buttons {
    display: flex;
    gap: 1rem;
    justify-content: center;
    flex-wrap: wrap;
}

.btn {
    padding: 12px 24px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    display: inline-block;
}

.btn-primary {
    background: #fff;
    color: #667eea;
}

.btn-primary:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.2);
}

.btn-secondary {
    background: transparent;
    color: white;
    border: 2px solid white;
}

.btn-secondary:hover {
    background: white;
    color: #667eea;
}

/* 课程部分 */
.courses {
    padding: 80px 0;
    background: white;
}

.section-title {
    text-align: center;
    font-size: 2.5rem;
    font-weight: 700;
    margin-bottom: 3rem;
    color: #2d3748;
}

.courses-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(350px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.course-card {
    background: white;
    border-radius: 16px;
    padding: 2rem;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    transition: all 0.3s ease;
    border: 1px solid #e2e8f0;
}

.course-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 12px 40px rgba(0,0,0,0.15);
}

.course-icon {
    width: 60px;
    height: 60px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    margin-bottom: 1.5rem;
}

.course-icon i {
    font-size: 1.5rem;
    color: white;
}

.course-title {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: #2d3748;
}

.course-description {
    color: #718096;
    margin-bottom: 1.5rem;
    line-height: 1.6;
}

.course-content h4 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: #2d3748;
}

.course-content ul {
    list-style: none;
    margin-bottom: 1rem;
}

.course-content li {
    padding: 0.5rem 0;
    color: #4a5568;
    position: relative;
    padding-left: 1.5rem;
}

.course-link {
    color: #667eea;
    text-decoration: none;
    font-weight: 500;
}

.course-link:hover {
    text-decoration: underline;
}

.course-content li:before {
    content: "✓";
    position: absolute;
    left: 0;
    color: #48bb78;
    font-weight: bold;
}

.course-steps h4 {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 0.75rem;
    color: #2d3748;
}

.course-steps ol {
    padding-left: 1.5rem;
    color: #4a5568;
}

.course-steps li {
    padding: 0.25rem 0;
}

.course-content a {
    color: #667eea;
    text-decoration: none;
    font-weight: 500;
}

.course-content a:hover {
    text-decoration: underline;
}

/* 美化链接样式 */
/* .course-description a[href*="survivesjtu.gitbook.io"],
.course-content a[href*="survivesjtu.gitbook.io"] {
    display: inline-block;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    text-decoration: none;
    font-weight: 600;
    padding: 8px 16px;
    border-radius: 8px;
    font-size: 0.9rem;
    transition: all 0.3s ease;
    box-shadow: 0 2px 8px rgba(102, 126, 234, 0.3);
    border: none;
    margin: 0 4px;
} */

.course-description a[href*="survivesjtu.gitbook.io"]:hover,
.course-content a[href*="survivesjtu.gitbook.io"]:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
    text-decoration: none;
}

.course-description a[href*="survivesjtu.gitbook.io"]:active,
.course-content a[href*="survivesjtu.gitbook.io"]:active {
    transform: translateY(0);
    box-shadow: 0 2px 8px rgba(102, 126, 234, 0.3);
}

/* 美化其他重要链接 */
.course-description a[href*="survivesjtu.gitbook.io"],
.course-content a[href*="survivesjtu.gitbook.io"],
.course-description a[href*="csdiy.wiki"],
.course-content a[href*="csdiy.wiki"],
.course-description a[href*="missing-semester-cn.github.io"],
.course-description a[href*="missing-semester.org"],
.course-description a[href*="https://www.youtube.com/@MissingSemester"],
.course-content a[href*="missing-semester-cn.github.io"],
.course-content a[href*="missing-semester.org"],
.course-content a[href*="https://www.youtube.com/@MissingSemester"],
.course-description a[href*="leetcode.cn"],
.course-content a[href*="leetcode.cn"],
.course-description a[href*="labuladong.online"],
.course-content a[href*="labuladong.online"] {
    display: inline-block !important;
    background: linear-gradient(135deg, #4872bb 0%, #38a169 100%) !important;
    color: white !important;
    text-decoration: none !important;
    font-weight: 600 !important;
    padding: 6px 12px !important;
    border-radius: 6px !important;
    font-size: 0.85rem !important;
    transition: all 0.3s ease !important;
    box-shadow: 0 2px 6px rgba(72, 187, 120, 0.3) !important;
    border: none !important;
    margin: 0 3px !important;
}

.course-description a[href*="csdiy.wiki"]:hover,
.course-content a[href*="csdiy.wiki"]:hover,
.course-description a[href*="missing-semester-cn.github.io"]:hover,
.course-content a[href*="missing-semester-cn.github.io"]:hover,
.course-description a[href*="missing-semester.org"]:hover,
.course-content a[href*="missing-semester.org"]:hover,
.course-description a[href*="https://www.youtube.com/@MissingSemester"]:hover,
.course-content a[href*="https://www.youtube.com/@MissingSemester"]:hover,
.course-description a[href*="leetcode.cn"]:hover,
.course-content a[href*="leetcode.cn"]:hover,
.course-description a[href*="labuladong.online"]:hover,
.course-content a[href*="labuladong.online"]:hover {
    transform: translateY(-2px) !important;
    box-shadow: 0 4px 12px rgba(72, 187, 120, 0.4) !important;
    text-decoration: none !important;
}

/* 美化GitHub链接 */
.author-text a[href*="github.com"] {
    display: inline-block;
    background: linear-gradient(135deg, #4a51ba 0%, #586069 100%);
    color: white;
    text-decoration: none;
    font-weight: 600;
    padding: 8px 16px;
    border-radius: 8px;
    font-size: 0.9rem;
    transition: all 0.3s ease;
    box-shadow: 0 2px 8px rgba(36, 41, 46, 0.3);
    border: none;
    margin: 0 4px;
}

.author-text a[href*="github.com"]:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(36, 41, 46, 0.4);
    text-decoration: none;
}

/* 美化邮箱链接 */
.author-text a[href^="mailto:"] {
    display: inline-block;
    background: linear-gradient(135deg, #3ed2e5 0%, #5ec2d2 100%);
    color: white;
    text-decoration: none;
    font-weight: 600;
    padding: 8px 16px;
    border-radius: 8px;
    font-size: 0.9rem;
    transition: all 0.3s ease;
    box-shadow: 0 2px 8px rgba(229, 62, 62, 0.3);
    border: none;
    margin: 0 4px;
}

.author-text a[href^="mailto:"]:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(229, 62, 62, 0.4);
    text-decoration: none;
}

/* 关于部分 */
.about {
    padding: 80px 0;
    background: #f8fafc;
}

.about-content {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 3rem;
    align-items: start;
}

.about-text h3 {
    font-size: 1.5rem;
    font-weight: 600;
    margin-bottom: 1rem;
    color: #2d3748;
}

.about-text ul {
    list-style: none;
    margin-bottom: 2rem;
}

.about-text li {
    padding: 0.5rem 0;
    color: #4a5568;
    position: relative;
    padding-left: 1.5rem;
}

.about-text li:before {
    content: "•";
    position: absolute;
    left: 0;
    color: #667eea;
    font-weight: bold;
    font-size: 1.2rem;
}

.about-quote {
    background: white;
    padding: 2rem;
    border-radius: 12px;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    border-left: 4px solid #667eea;
}

.about-quote blockquote {
    font-style: italic;
    font-size: 1.1rem;
    color: #4a5568;
    line-height: 1.6;
}

/* 作者部分 */
.author {
    padding: 80px 0;
    background: #f8fafc;
}

.author-content {
    max-width: 800px;
    margin: 0 auto;
    text-align: center;
}

.author-text p {
    color: #4a5568;
    line-height: 1.7;
    margin-bottom: 1rem;
    font-size: 1.1rem;
}

.author-text a {
    color: #667eea;
    text-decoration: none;
    font-weight: 500;
}

.author-text a:hover {
    text-decoration: underline;
}



/* 页脚 */
.footer {
    background: #2d3748;
    color: white;
    padding: 3rem 0;
    text-align: center;
}

.footer p {
    margin-bottom: 0.5rem;
    opacity: 0.9;
}

.footer i {
    color: #fc8181;
}

/* 响应式设计 */
@media (max-width: 768px) {
    .hero-title {
        font-size: 2.5rem;
    }
    
    .hero-subtitle {
        font-size: 1.1rem;
    }
    
    .hero-buttons {
        flex-direction: column;
        align-items: center;
    }
    
    .courses-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
    
    .about-content {
        grid-template-columns: 1fr;
        gap: 2rem;
    }
    
    .nav-menu {
        display: none;
    }
    
    .section-title {
        font-size: 2rem;
    }
}

@media (max-width: 480px) {
    .hero-title {
        font-size: 2rem;
    }
    
    .course-card {
        padding: 1.5rem;
    }
    
    .container {
        padding: 0 15px;
    }
}

/* 动画效果 */
@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(30px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.course-card {
    animation: fadeInUp 0.6s ease-out;
}

/* 课程操作按钮 */
.course-actions {
    margin-top: 1.5rem;
    text-align: center;
}

.btn {
    display: inline-block;
    padding: 12px 24px;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
    transition: all 0.3s ease;
    border: none;
    cursor: pointer;
    font-size: 0.95rem;
}

.btn-primary {
    background: #667eea;
    color: white;
}

.btn-primary:hover {
    background: #5a67d8;
    transform: translateY(-2px);
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
}

.course-card:nth-child(1) { animation-delay: 0.1s; }
.course-card:nth-child(2) { animation-delay: 0.2s; }
.course-card:nth-child(3) { animation-delay: 0.3s; }
.course-card:nth-child(4) { animation-delay: 0.4s; }
.course-card:nth-child(5) { animation-delay: 0.5s; }
.course-card:nth-child(6) { animation-delay: 0.6s; }

/* 专门针对CS DIY链接的样式，确保优先级 */
p.course-description a[href*="csdiy.wiki"] {
    display: inline-block !important;
    background: linear-gradient(135deg, #4872bb 0%, #38a169 100%) !important;
    color: white !important;
    text-decoration: none !important;
    font-weight: 600 !important;
    padding: 6px 12px !important;
    border-radius: 6px !important;
    font-size: 0.85rem !important;
    transition: all 0.3s ease !important;
    box-shadow: 0 2px 6px rgba(72, 187, 120, 0.3) !important;
    border: none !important;
    margin: 0 3px !important;
}

p.course-description a[href*="csdiy.wiki"]:hover {
    transform: translateY(-2px) !important;
    box-shadow: 0 4px 12px rgba(72, 187, 120, 0.4) !important;
    text-decoration: none !important;
}