/* 全局样式 */
body {
    font-family: "Arial", sans-serif;
    max-width: 900px;
    margin: auto;
    padding: 20px;
    background-color: #f8f9fa;
    color: #333;
}

/* 顶部导航栏 */
nav {
    background: #007bff;
    padding: 10px;
    text-align: center;
    border-radius: 8px;
    display: flex;
    justify-content: center;
    gap: 10px;
}

nav a {
    color: white;
    text-decoration: none;
    font-weight: bold;
    padding: 8px 12px;
    border-radius: 5px;
}

nav a:hover {
    background: #0056b3;
}

/* 汉堡菜单按钮 */
.menu-toggle {
    display: none;
    background: #007bff;
    color: white;
    border: none;
    padding: 10px;
    font-size: 18px;
    cursor: pointer;
    border-radius: 5px;
    width: 100%;
    text-align: center;
}

/* 手机端优化导航栏 */
@media (max-width: 768px) {
    .menu-toggle {
        display: block;
    }
    
    .menu {
        display: none;
        flex-direction: column;
        align-items: center;
        width: 100%;
        padding: 10px;
        background: #007bff;
        border-radius: 5px;
    }
    
    .menu.active {
        display: flex;
    }
    
    .menu a {
        display: block;
        width: 100%;
        text-align: center;
        padding: 10px;
        color: white;
        text-decoration: none;
    }
    
    .menu a:hover {
        background: #0056b3;
    }
}

/* 内容区域 */
main {
    margin-top: 20px;
    padding: 20px;
    background: white;
    border-radius: 8px;
    box-shadow: 0px 0px 10px rgba(0, 0, 0, 0.1);
}

/* 页脚 */
footer {
    margin-top: 40px;
    text-align: center;
    font-size: 14px;
    padding: 10px;
    background: #007bff;
    color: white;
    border-radius: 5px;
}