body {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
    background-color: #f0f0f5; /* 柔和的背景色 */
    margin: 0;
    padding: 0;
    display: flex;
    flex-direction: column; /* 确保内容上下排列 */
    align-items: center; /* 内容居中对齐 */
}

header {
    background-color: #007aff; /* 蓝色背景 */
    color: white;
    text-align: center;
    width: 100%;
    padding: 20px 0;
    box-shadow: 0 4px 10px rgba(0, 0, 0, 0.1);
    border-bottom: 1px solid rgba(0, 0, 0, 0.1);
}

h1 {
    font-size: 1.5em; /* 调整字体大小 */
    margin: 0;
    letter-spacing: 1px;
}

.metro-nav {
    display: grid;
    grid-template-columns: repeat(5, 1fr); /* 5列 */
    gap: 30px;
    padding: 30px;
    width: 100%;
    max-width: 1200px;
}

.metro-column {
    display: flex;
    flex-direction: column;
    gap: 20px;
    padding: 20px;
    background-color: white;
    border-radius: 12px;
    box-shadow: 0 2px 15px rgba(0, 0, 0, 0.05);
    transition: all 0.5s ease;
}

.metro-column:hover {
    box-shadow: 0 2px 30px rgba(0, 0, 0, 0.1);
}

.column-title {
    font-size: 1.2em;
    color: #333;
    margin-bottom: 15px;
    text-align: center; /* 居中显示标题 */
    text-transform: uppercase;
    letter-spacing: 1px;
}

.metro-tile {
    background-color: #007aff; /* 蓝色按钮 */
    color: white;
    padding: 20px;
    border-radius: 12px;
    text-align: center;
    box-shadow: 0px 2px 10px rgba(0, 0, 0, 0.1);
    transition: all 0.3s ease;
    text-decoration: none;
    display: flex;
    justify-content: center;
    align-items: center;
    height: 60px;
    font-size: 0.6em;
    border: none;
}

.metro-tile:hover {
    transform: translateY(-4px);
    box-shadow: 0px 6px 20px rgba(0, 0, 0, 0.1);
}

.metro-tile a {
    color: white;
    text-decoration: none;
}

.disabled {
    background-color: #d3d3d3; /* 灰色按钮 */
    color: #a5a5a5;
    pointer-events: none; /* 禁用点击 */
    box-shadow: none;
    height: 60px; /* 确保禁用按钮与正常按钮一致 */
}

.logo-section {
    display: flex;
    justify-content: center; /* 居中显示 logo */
    gap: 30px;
    background-color: white;
    padding: 30px;
    width: 100%;
    max-width: 1145px;
    margin: 20px auto;
    border-radius: 12px;
    box-shadow: 0 2px 15px rgba(0, 0, 0, 0.1);
    flex-wrap: wrap; /* 允许 logo 在空间不足时换行 */
}

.logo {
    width: 150px; /* 调整大小 */
    height: auto;
    opacity: 0.8;
    transition: opacity 0.3s;
    flex: 1 1 20%; /* 使 logo 在宽屏下占 20% 宽度，适应不同屏幕 */
    max-width: 150px; /* 设置最大宽度 */
    margin-bottom: 10px; /* 给每个 logo 留些底部间距 */
}

.logo:hover {
    opacity: 1; /* 鼠标悬停时增加透明度 */
}

footer {
    background-color: #007aff; /* 蓝色底部 */
    color: white;
    text-align: center;
    padding: 15px 0;
    position: relative;
    width: 100%;
    font-size: 1em;
}

footer p {
    margin: 0;
}