/* 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: #f9f9f9;
    padding: 20px;
}

.container {
    max-width: 1000px;
    margin: 0 auto;
    background-color: #fff;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0, 0, 0, 0.1);
}

/* 标题样式 */
header {
    text-align: center;
    margin-bottom: 30px;
    padding-bottom: 20px;
    border-bottom: 1px solid #eee;
}

h1 {
    font-size: 2.5rem;
    color: #2c3e50;
    margin-bottom: 10px;
}

h2 {
    font-size: 1.8rem;
    color: #3498db;
    margin: 30px 0 15px;
    padding-bottom: 10px;
    border-bottom: 1px solid #eee;
}

h3 {
    font-size: 1.4rem;
    color: #2c3e50;
    margin: 20px 0 10px;
}

/* 段落和列表样式 */
p {
    margin-bottom: 15px;
}

ul, ol {
    margin: 15px 0 15px 20px;
}

li {
    margin-bottom: 8px;
}

ul ul, ol ol, ul ol, ol ul {
    margin-top: 8px;
    margin-bottom: 8px;
}

/* 章节样式 */
section {
    margin-bottom: 30px;
}

section.intro {
    background-color: #f8f9fa;
    padding: 20px;
    border-left: 4px solid #3498db;
    margin-bottom: 30px;
}

/* 链接样式 */
a {
    color: #3498db;
    text-decoration: none;
    transition: color 0.3s;
}

a:hover {
    color: #2980b9;
    text-decoration: underline;
}

/* 页脚样式 */
footer {
    margin-top: 40px;
    padding-top: 20px;
    border-top: 1px solid #eee;
    text-align: center;
    font-size: 0.9rem;
    color: #7f8c8d;
}

footer p {
    margin-bottom: 10px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    body {
        padding: 10px;
    }
    
    .container {
        padding: 20px;
    }
    
    h1 {
        font-size: 2rem;
    }
    
    h2 {
        font-size: 1.5rem;
    }
    
    h3 {
        font-size: 1.2rem;
    }
}

@media (max-width: 480px) {
    h1 {
        font-size: 1.8rem;
    }
    
    h2 {
        font-size: 1.3rem;
    }
    
    h3 {
        font-size: 1.1rem;
    }
    
    .container {
        padding: 15px;
    }
}