/* 全局样式 */
body {
    margin: 0;
    font-family: 'Poppins', sans-serif;
    background: radial-gradient(circle, #E8F0FF, #DED8FA);
    color: #333;
}
header {
    padding: 20px;
    text-align: center;
    background: rgba(255, 255, 255, 0.3);
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
}
.sidebar {
    position: fixed;
    left: 0;
    top: 0;
    width: 220px;
    height: 100%;
    background: rgba(255, 255, 255, 0.2);
    backdrop-filter: blur(10px);
    padding: 20px;
    box-shadow: 2px 0 5px rgba(0,0,0,0.1);
}
.sidebar a {
    display: block;
    color: #333;
    text-decoration: none;
    margin-bottom: 15px;
    transition: color 0.3s;
}
.sidebar a:hover {
    color: #FFA726;
}
.main {
    margin-left: 240px;
    padding: 20px;
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
}
.card {
    background: rgba(255, 255, 255, 0.7);
    border-radius: 10px;
    box-shadow: 0 4px 10px rgba(0,0,0,0.1);
    padding: 15px;
    transition: transform 0.3s, box-shadow 0.3s;
    width: calc(33.333% - 40px);
}
.card:hover {
    transform: scale(1.05);
    box-shadow: 0 8px 20px rgba(0,0,0,0.2);
}
.card img {
    width: 100%;
    border-radius: 8px;
}
.example-article {
    width: 100%;
    background: rgba(255, 255, 255, 0.8);
    padding: 20px;
    border-radius: 10px;
    margin-top: 40px;
}
.example-article h2, .example-article h3, .example-article p, .example-article table {
    margin-bottom: 15px;
}
.example-article pre {
    background: #f5f5f5;
    padding: 10px;
    border-radius: 5px;
    overflow-x: auto;
}
footer {
    text-align: center;
    padding: 20px;
    background: rgba(255, 255, 255, 0.3);
    box-shadow: 0 -4px 10px rgba(0,0,0,0.1);
    position: fixed;
    width: 100%;
    bottom: 0;
}
@media (max-width: 1200px){
    .card {width: calc(50% - 40px);}
}
@media (max-width: 768px){
    .card {width: 100%;}
    .sidebar {width: 100%; height: auto; position: relative;}
    .main {margin-left: 0;}
}