body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f7f7f7;
}
.banner {
    background-color: #f7f7f7; /* 与网页背景颜色一致 */
    color: #4CAF50;
    padding: 1em;
    display: flex;
    align-items: center;
    justify-content: flex-start;
    position: fixed;
    top: 0;
    width: 100%;
    z-index: 1000;
}
.banner .title {
    font-size: 1.5em;
    margin: 0;
}

nav {
    background-color: #4CAF50;
    color: white;
    width: 100%;
    position: fixed;
    top: 50px; /* banner 高度 */
    z-index: 1000;
    transition: background-color 0.3s;
}
nav ul {
    list-style: none;
    display: flex;
    justify-content: space-around;
    padding: 0;
    margin: 0;
}
nav ul li {
    margin: 0;
}
nav ul li a {
    color: white;
    text-decoration: none;
    padding: 0.5em 1em;
    display: block;
    transition: background-color 0.3s, transform 0.3s;
}
nav ul li a:hover {
    background-color: #575757;
    transform: translateY(-5px);
}
.container {
    margin-top: 120px; /* 调整以适应固定的banner和nav */
    padding: 1em;
}
.section {
    display: none;
    margin-bottom: 2em;
}
.section.active {
    display: block;
}
.grid {
    display: flex;
    flex-wrap: wrap;
    gap: 1em;
    justify-content: center;
}
.fg{
    text-align: center;
    font-size: 18px;
	font-weight:bold;
	padding:18px 1px;
    display: flex;
    justify-content: center;
    align-items: center;
}
.card {
    background-color: white;
    border-radius: 10px;
    box-shadow: 0 4px 8px rgba(0, 0, 0, 0.1);
    overflow: hidden;
    transition: transform 0.3s, box-shadow 0.3s;
    max-width: 400px;
    width: 100%;
    height: 200px;
    position: relative;
}
.card img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    position: absolute;
    top: 0;
    left: 0;
}
.card .info {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    background: rgba(0, 0, 0, 0.6);
    color: white;
    text-align: center;
    width: 90%;
    padding: 0.5em;
    border-radius: 5px;
}
.card:hover {
    transform: translateY(-10px);
    box-shadow: 0 8px 16px rgba(0, 0, 0, 0.2);
}
@media (max-width: 768px) {
    .card {
        max-width: 100%;
    }
}
@media (max-width: 480px) {
    .card {
        max-width: 100%;
    }
}