* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    font-family: "Microsoft YaHei", Arial, sans-serif;
}
body {
    max-width: 1200px;
    margin: 0 auto;
    padding: 20px;
    line-height: 1.8;
    color: #333;
    background-color: #f4f4f9;
}
.main-nav {
    background-color: #2c3e50;
    border-radius: 8px;
    margin-bottom: 20px;
    padding: 10px 0;
}
.main-nav ul {
    list-style: none;
    display: flex;
    justify-content: center;
}
.main-nav li {
    margin: 0 15px;
}
.main-nav a {
    color: #ffffff;
    text-decoration: none;
    font-size: 1.1rem;
    padding: 10px 15px;
    border-radius: 5px;
    transition: background-color 0.3s;
}
.main-nav a:hover {
    background-color: #34495e;
}
.header {
    text-align: center;
    margin: 40px 0;
    padding: 20px 0;
    background-color: #ffffff;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}
.header h1 {
    font-size: 3rem;
    color: #2c3e50;
    margin-bottom: 10px;
}
.header p {
    font-size: 1.1rem;
    color: #7f8c8d;
}
.intro {
    max-width: 800px;
    margin: 0 auto 60px;
    padding: 30px;
    background-color: #ffffff;
    border-radius: 8px;
    border-left: 5px solid #3498db;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}
.intro h2 {
    font-size: 1.8rem;
    color: #2c3e50;
    margin-bottom: 20px;
}
.intro p {
    font-size: 1.1rem;
    margin-bottom: 15px;
    color: #555;
}
.directory {
    max-width: 800px;
    margin: 0 auto 80px;
    background-color: #ffffff;
    padding: 30px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
}
.directory h2 {
    font-size: 1.8rem;
    color: #2c3e50;
    margin-bottom: 25px;
    padding-bottom: 15px;
    border-bottom: 2px solid #f1f1f1;
    text-align: center;
}
.dir-list {
    list-style: none;
}
.dir-list li {
    margin-bottom: 18px;
    text-align: center;
}
.dir-list a {
    font-size: 1.2rem;
    color: #3498db;
    text-decoration: none;
    transition: all 0.3s ease;
    display: block;
    padding: 10px;
    border-radius: 5px;
    background-color: #f8f9fa;
}
.dir-list a:hover {
    color: #ffffff;
    background-color: #3498db;
    text-decoration: none;
    transform: translateY(-2px);
    box-shadow: 0 4px 6px rgba(52,152,219,0.2);
}
.footer {
    text-align: center;
    padding: 25px 0;
    border-top: 1px solid #ddd;
    margin-top: 60px;
    font-size: 0.9rem;
}
.footer a {
    color: #666;
    text-decoration: none;
    transition: color 0.3s;
}
.footer a:hover {
    color: #333;
    text-decoration: underline;
}
.category-image {
    width: 100%;
    height: auto;
    border-radius: 8px;
    margin-bottom: 30px;
}
.article-list {
    list-style: none;
    padding: 0;
}
.article-list li {
    background-color: #ffffff;
    padding: 20px;
    margin-bottom: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0,0,0,0.1);
    transition: transform 0.3s;
}
.article-list li:hover {
    transform: translateY(-5px);
}
.article-list h3 {
    margin-bottom: 10px;
    color: #2c3e50;
}
.article-list p {
    color: #555;
}
.article-list a {
    text-decoration: none;
    color: inherit;
}
.article-content {
    padding: 20px;
}