@charset "utf-8";
/* CSS Document */

#guild{ width: 100%; display: flex;flex-wrap: wrap; margin: 2rem auto; }
#guild a{ display: block; width: 30%; padding: 2rem 1rem; text-align: center}


        .header-container {
            width: 100%;
            height: 70px; /* 明确指定高度，方便计算 padding-top */
            background: linear-gradient(to bottom, #dcebf7 0%, #c3ddf5 100%);

            /* --- 关键修改开始 --- */
            position: fixed; /* 固定定位，脱离文档流 */
            top: 0;          /* 紧贴顶部 */
            left: 0;         /* 紧贴左侧 */
            z-index: 1000;   /* 极高优先级，确保覆盖在所有内容之上 */
            box-shadow: 0 2px 10px rgba(0,0,0,0.1); /* 增加一点阴影增强立体感 */
            /* --- 关键修改结束 --- */
        }

        .container {
            max-width: 1500px;
            margin: 0 auto;
            height: 100%;
            display: flex;
            justify-content: space-between;
            align-items: center;
            padding: 0 20px;
        }

        /* Logo 区域 */
        .logo img {
            height: 50px; /* 限制Logo高度以适应导航条 */
            display: block;
        }

        /* 3. 桌面端导航菜单 */
        .nav-list {
            display: flex;
            gap: 20px;
        }

        .nav-list > li {
            position: relative; /* 用于下拉菜单定位 */
        }

        .nav-list > li > a {
            font-size: 16px;
            color: #333;
            font-weight: bold;
            padding: 10px 0;
            display: block;
            transition: color 0.3s;
        }

        .nav-list > li > a:hover {
            color: #0056b3; /* 悬停变蓝 */
        }

        /* 下拉菜单样式 */
        .dropdown-menu {
            display: none; /* 默认隐藏 */
            position: absolute;
            top: 100%;
            left: 0;
            background-color: #fff;
            min-width: 150px;
            box-shadow: 0 4px 8px rgba(0,0,0,0.1);
            border-top: 2px solid #0056b3;
            z-index: 1001;
        }

        .dropdown-menu li a {
            display: block;
            padding: 12px 20px;
            color: #555;
            font-size: 14px;
            border-bottom: 1px solid #eee;
        }

        .dropdown-menu li a:hover {
            background-color: #f9f9f9;
            color: #0056b3;
        }

        /* 鼠标悬停显示下拉菜单 (桌面端) */
        @media (min-width: 769px) {
            .dropdown:hover .dropdown-menu {
                display: block;
            }
        }

        /* 汉堡菜单按钮 (默认隐藏) */
        .menu-toggle {
            display: none;
            flex-direction: column;
            cursor: pointer;
            gap: 5px;
        }

        .bar {
            width: 25px;
            height: 3px;
            background-color: #333;
            border-radius: 2px;
        }

        /* 4. 响应式适配 (手机端) */
        @media (max-width: 768px) {
            .menu-toggle {
                display: flex; /* 显示汉堡按钮 */
            }

            .nav-list {
                display: none; /* 默认隐藏菜单列表 */
                position: absolute;
                top: 70px; /* 在Header正下方展开 */
                left: 0;
                width: 100%;
                background-color: #fff;
                flex-direction: column;
                box-shadow: 0 4px 8px rgba(0,0,0,0.1);
                padding: 10px 0;
            }

            /* JS激活时显示的类 */
            .nav-list.active {
                display: flex;
            }

            .nav-list > li {
                width: 100%;
                text-align: center;
                border-bottom: 1px solid #f0f0f0;
            }

            .nav-list > li > a {
                padding: 15px 0;
            }

            /* 移动端下拉菜单处理：改为相对定位，推挤下方内容 */
            .dropdown-menu {
                position: static;
                box-shadow: none;
                border-top: none;
                background-color: #f8f9fa;
                display: none; /* 依然默认隐藏，需点击触发 */
            }

            .dropdown-menu.show {
                display: block;
            }

            .dropdown-menu li a {
                text-align: center;
                border-bottom: none;
            }
        }

        /* 模拟长内容以便测试滚动效果 */
        .main-content {
            padding: 20px;
            max-width: 1200px;
            margin: 0 auto;
        }
        .banner-placeholder {
            width: 100%;
            height: 400px;
            background-color: #ddd;
            display: flex;
            align-items: center;
            justify-content: center;
            font-size: 24px;
            color: #666;
            margin-bottom: 20px;
            background-image: url('https://via.placeholder.com/1200x400?text=校园风光+Banner');
            background-size: cover;
        }
        .content-block {
            height: 800px; /* 制造足够长的滚动区域 */
            background: white;
            padding: 40px;
            margin-bottom: 20px;
            border-radius: 8px;
        }