/* 全局样式 */
* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    line-height: 1.6;
    color: #333;
    background-color: #f8f9fa;
}

/* 头部样式 */
header {
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 2rem 0;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

header h1 {
    text-align: center;
    font-size: 2.5rem;
    margin-bottom: 1rem;
    font-weight: 300;
}

/* 导航样式 */
nav {
    text-align: center;
}

nav ul {
    list-style: none;
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 2rem;
}

nav a {
    color: white;
    text-decoration: none;
    font-weight: 500;
    padding: 0.5rem 1rem;
    border-radius: 25px;
    transition: all 0.3s ease;
}

nav a:hover {
    background-color: rgba(255,255,255,0.2);
    transform: translateY(-2px);
}

/* 主内容区域 */
main {
    max-width: 1200px;
    margin: 0 auto;
    padding: 3rem 2rem;
    background: white;
    margin-top: -1rem;
    border-radius: 10px 10px 0 0;
    box-shadow: 0 -2px 10px rgba(0,0,0,0.1);
}

/* 章节样式 */
section {
    margin: 3rem 0;
    padding: 2rem 0;
}

section h2 {
    color: #667eea;
    font-size: 2rem;
    margin-bottom: 1.5rem;
    border-bottom: 3px solid #667eea;
    padding-bottom: 0.5rem;
    display: inline-block;
}

section p {
    font-size: 1.1rem;
    line-height: 1.8;
    margin-bottom: 1rem;
    color: #555;
}

/* 项目网格 */
.project-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(300px, 1fr));
    gap: 2rem;
    margin-top: 2rem;
}

.project-card {
    background: white;
    border: 1px solid #e9ecef;
    border-radius: 10px;
    padding: 2rem;
    box-shadow: 0 4px 6px rgba(0,0,0,0.1);
    transition: all 0.3s ease;
}

.project-card:hover {
    transform: translateY(-5px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.15);
}

.project-card h3 {
    color: #667eea;
    margin-bottom: 1rem;
    font-size: 1.5rem;
}

.project-card h3 a {
    color: inherit;
    text-decoration: none;
    transition: color 0.3s ease;
}

.project-card h3 a:hover {
    color: #5a6fd8;
}

.project-card p {
    color: #666;
    font-size: 1rem;
}

/* 页脚样式 */
footer {
    background: #333;
    color: white;
    text-align: center;
    padding: 2rem 0;
    margin-top: 3rem;
}

/* 响应式设计 */
@media (max-width: 768px) {
    header h1 {
        font-size: 2rem;
    }
    
    nav ul {
        flex-direction: column;
        gap: 1rem;
    }
    
    main {
        padding: 2rem 1rem;
        margin: 0;
        border-radius: 0;
    }
    
    section {
        margin: 2rem 0;
        padding: 1rem 0;
    }
    
    .project-grid {
        grid-template-columns: 1fr;
        gap: 1.5rem;
    }
}

/* 链接样式 */
a {
    color: #667eea;
    text-decoration: none;
    transition: color 0.3s ease;
}

a:hover {
    color: #5a6fd8;
    text-decoration: underline;
}

/* 代码样式 */
code {
    background: #f8f9fa;
    padding: 0.2rem 0.4rem;
    border-radius: 3px;
    font-family: 'Courier New', monospace;
    font-size: 0.9rem;
    color: #e83e8c;
}

pre {
    background: #f8f9fa;
    padding: 1rem;
    border-radius: 5px;
    overflow-x: auto;
    margin: 1rem 0;
}

pre code {
    background: none;
    padding: 0;
    color: #333;
}