* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
            font-family: "Microsoft Yahei", sans-serif;
        }
        /* ===== 全屏视频背景层（固定，内容可在其上层滚动） ===== */
        .banner {
            position: fixed;
            top: 0;
            left: 0;
            width: 100%;
            height: 100%;
            z-index: -1;
            overflow: hidden;
        }
        .bg-video {
            position: absolute;
            top: 50%;
            left: 50%;
            transform: translate(-50%, -50%);
            min-width: 100%;
            min-height: 100%;
            z-index: 1;
            object-fit: cover;
        }
        .banner-mask {
            position: absolute;
            width:100%;
            height:100%;
            background: rgba(0,0,0,0.25);
            z-index: 2;
        }


        /* ===== 顶部导航栏 ===== */
        header{
            display:flex;
            justify-content: space-between;
            align-items:center;
            padding:24px 40px;
            color:#fff;
            z-index:2;
            position:relative;
        }
        .logo{
            font-size:24px;
            color:#40bfff;
            font-weight:bold;
        }
        .nav-menu a{
            color:#fff;
            text-decoration:none;
            margin-left:20px;
            font-size:16px;
        }
        .nav-menu a:hover{
            text-decoration:underline;
        }

        /* ===== 页面标题 ===== */
        .page-title{
            text-align:center;
            padding:50px 20px 40px;
            color:#fff;
            position:relative;
            z-index:2;
        }
        .page-title h1{
            font-size:44px;
            margin-bottom:14px;
        }
        .page-title p{
            font-size:17px;
            opacity:0.85;
        }

        /* ===== 主体容器，4个磨砂卡片网格布局 ===== */
        .container{
            max-width:1100px;
            margin:0 auto;
            padding:0 20px 60px;
            position:relative;
            z-index:2;
            display:grid;
            grid-template-columns: repeat(2, 1fr);
            gap:28px;
        }
        /* 磨砂卡片通用样式 */
        .glass-card{
            background: rgba(255,255,255,0.15);
            backdrop-filter: blur(14px);
            border:1px solid rgba(255,255,255,0.3);
            border-radius:14px;
            padding:30px;
            color:#fff;
            transition:0.3s;
        }
        .glass-card:hover{
            background: rgba(255,255,255,0.22);
            transform: translateY(-4px);
        }
        .glass-card h2{
            font-size:24px;
            margin-bottom:20px;
            display:flex;
            align-items:center;
            gap:10px;
        }
        .folder-list{
            list-style:none;
        }
        .folder-list li{
            padding:10px 0;
            border-bottom:1px solid rgba(255,255,255,0.15);
        }
        .folder-list li:last-child{
            border-bottom:none;
        }
        .folder-list a{
            color:#fff;
            text-decoration:none;
            opacity:0.9;
        }
        .folder-list a:hover{
            opacity:1;
            text-decoration:underline;
        }

        /* 右侧悬浮按钮（和其他页面保持一致） */
        .float-side-btn{
            position:fixed;
            right:24px;
            top:120px;
            display:flex;
            flex-direction:column;
            gap:12px;
            z-index:99;
        }
        .float-circle-btn{
            width:40px;
            height:40px;
            border-radius:50%;
            background: rgba(255,255,255,0.15);
            backdrop-filter: blur(12px);
            border:1px solid rgba(255,255,255,0.3);
            color:#fff;
            display:flex;
            align-items:center;
            justify-content:center;
            cursor:pointer;
        }
        .float-avatar{
            position:fixed;
            right:16px;
            top:260px;
            width:60px;
            height:60px;
            border-radius:50%;
            background: rgba(255,255,255,0.15);
            backdrop-filter: blur(12px);
            border:1px solid rgba(255,255,255,0.3);
            z-index:99;
        }

        /* 手机适配，自动单列 */
        @media (max-width:720px){
            .container{
                grid-template-columns:1fr;
            }
        }