body {  
    font-family: 'Georgia', serif; /* 使用更古典的字体 */  
    background-color: #f9f7f7; /* 温和的背景色 */  
    color: #4e4e4e;  
    line-height: 1.6;  
    margin: 0;  
    padding: 0;  
    background-image: url('background-pattern.png'); /* 可添加背景图案 */  
    background-size: cover;  
}  

header {  
    background-color: #e3d4c0; 
    color: goldenrod;  
    padding: 15px 0;  
    text-align: center;  
    position: relative; /* 为绝对定位的元素腾出空间 */  
}  

h1 {  
    margin: 0;  
    font-size: 3em;  
    font-weight: bold;  
}  

nav {  
    margin-top: 10px;  
    display: flex;  
    justify-content: center;  
}  

nav a {  
    margin: 0 15px;  
    padding: 10px 20px;  
    background: rgba(255, 255, 255, 0.8); /* 半透明的白色按钮 */  
    color: #6a4f8a;  
    text-decoration: none;  
    border-radius: 5px;  
    transition: background 0.3s, transform 0.2s;  
}  

nav a:hover {  
    background: rgba(255, 255, 255, 1);  
    transform: scale(1.05); /* 鼠标悬停时增长效果 */  
}  

main {  
    max-width: 800px;  
    margin: 20px auto;  
    padding: 20px;  
    background: white;  
    border-radius: 10px;  
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.1);  
}  

h2 {  
    color: #2980b9;  
    border-bottom: 2px solid #e74c3c;  
    padding-bottom: 10px;  
    font-size: 2em;  
}  

ol, ul {  
    margin: 20px 0;  
    padding-left: 20px;  
}  

li {  
    margin: 10px 0;  
}  

footer {  
    margin-top: 20px;  
    text-align: center;  
    font-style: italic;  
}  

.separator {  
    margin: 20px 0;  
    border-top: 1px solid #ddd;  
}