:root {
            --bg-color: #f8f9fa; 
            --card-bg: #ffffff;
            --hover-bg: #f0f0f0;
            --accent: #0078d4; /* Microsoft Blue */
            --accent-hover: #006abc;
            --text-main: #201f1e;
            --text-sub: #605e5c;
            --border-color: #e1dfdd;
            
            /* 阴影 */
            --shadow-rest: 0 2px 5px rgba(0,0,0,0.05), 0 0 1px rgba(0,0,0,0.1);
            --shadow-hover: 0 8px 16px rgba(0,0,0,0.1), 0 0 1px rgba(0,0,0,0.1);
            --shadow-modal: 0 25.6px 57.6px rgba(0,0,0,0.22), 0 4.8px 14.4px rgba(0,0,0,0.18);
            
            --radius: 6px;
            --sidebar-width: 72px; 
            --transition: all 0.25s cubic-bezier(0.1, 0.9, 0.2, 1);
        }

        * {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
            outline: none;
            -webkit-tap-highlight-color: transparent;
        }

        body {
            font-family: "Segoe UI", "Microsoft YaHei", sans-serif;
            background: linear-gradient(135deg, #f8f9fa 0%, #eff6fc 100%); 
            color: var(--text-main);
            height: 100vh;
            display: flex;
            overflow: hidden;
        }

        /* 左侧侧边栏 */
        .sidebar {
            width: var(--sidebar-width);
            background: var(--card-bg);
            display: flex;
            flex-direction: column;
            align-items: center;
            padding-top: 24px;
            box-shadow: 1px 0 0 var(--border-color);
            z-index: 100;
        }

        .sidebar-item {
            width: 56px;
            height: 56px;
            border-radius: var(--radius);
            display: flex;
            flex-direction: column;
            justify-content: center;
            align-items: center;
            margin-bottom: 12px;
            cursor: pointer;
            text-decoration: none;
            color: var(--text-sub);
            transition: var(--transition);
            background: transparent;
        }

        .sidebar-item:hover {
            background-color: var(--hover-bg);
            color: var(--accent);
        }

        .sidebar-item span {
            font-size: 10px; 
            margin-top: 4px;
            font-weight: 500;
            text-align: center;
            line-height: 1.2;
        }

        .icon-svg { width: 22px; height: 22px; fill: currentColor; }

        /* 主体区域 */
        .main-content {
            flex: 1;
            display: flex;
            flex-direction: column;
            align-items: center;
            padding: 40px 20px 0 20px;
            overflow-y: auto;
            position: relative;
        }

        .language-switch {
            font-size: 12px;
            color: var(--text-sub);
            text-decoration: none;
            padding: 6px 14px;
            background: #fff;
            backdrop-filter: blur(10px);
            -webkit-backdrop-filter: blur(10px);
            border: 1px solid rgba(0, 0, 0, 0.05);
            border-radius: 5px; 
            transition: var(--transition);
            font-weight: 500;
        }

        .language-switch:hover {
            background-color: #ffffff;
            color: var(--text-main);
            box-shadow: 0 2px 8px rgba(0, 0, 0, 0.05);
        }

        /* 垂直居中容器 */
        .center-container {
            width: 100%;
            max-width: 800px;
            margin-top: 15vh; 
            display: flex;
            flex-direction: column;
            align-items: center;
        }

        /* 搜索引擎板块 */
        .search-wrapper {
            width: 100%;
            max-width: 640px;
            margin-bottom: 48px;
        }

        .search-tabs {
            display: flex;
            gap: 20px;
            margin-bottom: 12px;
            padding-left: 12px;
        }

        .search-tab {
            font-size: 14px;
            color: var(--text-sub);
            cursor: pointer;
            padding-bottom: 6px;
            border-bottom: 2px solid transparent;
            transition: var(--transition);
            opacity: 0.8;
        }

        .search-tab:hover { opacity: 1; color: var(--text-main); }

        .search-tab.active {
            color: var(--text-main);
            border-bottom-color: var(--accent);
            font-weight: 600;
            opacity: 1;
        }

        .search-box {
            background: var(--card-bg);
            border-radius: 30px; 
            box-shadow: var(--shadow-rest);
            display: flex;
            align-items: center;
            padding: 0 6px 0 20px; 
            height: 52px;
            border: 1px solid transparent;
            transition: box-shadow 0.2s, border-color 0.2s;
        }

        .search-box:hover, .search-box:focus-within {
            box-shadow: var(--shadow-hover);
            border-color: rgba(0,0,0,0.05);
        }

        .search-input {
            flex: 1;
            border: none;
            height: 100%;
            font-size: 16px;
            background: transparent;
            color: var(--text-main);
        }

        .search-btn {
            background: transparent;
            border: none;
            cursor: pointer;
            color: var(--accent);
            width: 44px;
            height: 44px;
            border-radius: 50%;
            display: flex;
            align-items: center;
            justify-content: center;
            transition: background 0.2s;
        }
        
        .search-btn:hover { background: var(--hover-bg); }

        /* 快捷链接板块 */
        .quick-links {
            display: grid;
            grid-template-columns: repeat(auto-fill, minmax(90px, 1fr));
            gap: 24px 16px;
            width: 100%;
            padding: 0 20px;
        }

        .link-card {
            display: flex;
            flex-direction: column;
            align-items: center;
            justify-content: center;
            padding: 15px 5px;
            border-radius: var(--radius);
            cursor: pointer;
            transition: var(--transition);
            text-decoration: none;
            color: var(--text-main);
            background: transparent;
        }

        .link-card:hover {
            background-color: var(--card-bg);
            box-shadow: var(--shadow-rest);
            transform: translateY(-3px);
        }

        .link-icon-box {
            width: 48px;
            height: 48px;
            margin-bottom: 10px;
            padding: 10px;
            border-radius: 12px;
            background-color: #fff; 
            display: flex;
            align-items: center;
            justify-content: center;
            overflow: hidden;
            box-shadow: 0 2px 4px rgba(0,0,0,0.05);
        }
        
        .link-icon-img {
            width: 100%;
            height: 100%;
        }

        .nav-trigger .link-icon-box {
            background-color: var(--accent);
            color: white;
        }

        .link-title {
            font-size: 13px;
            text-align: center;
            white-space: nowrap;
            overflow: hidden;
            text-overflow: ellipsis;
            width: 100%;
        }

        /* 导航弹窗 */
        .modal-overlay {
            position: fixed; top: 0; left: 0; width: 100vw; height: 100vh;
            background: rgba(0, 0, 0, 0.4); backdrop-filter: blur(8px); 
            z-index: 1000; display: flex; align-items: center; justify-content: center;
            visibility: hidden; opacity: 0; transition: all 0.3s;
        }
        .modal-overlay.open { visibility: visible; opacity: 1; }

        .modal-content {
            background: rgba(255, 255, 255, 0.96); backdrop-filter: blur(20px);
            width: 95%; 
            max-width: 1000px; 
            max-height: 88vh;  
            border-radius: 16px; box-shadow: var(--shadow-modal);
            padding: 40px 50px; 
            overflow-y: auto; position: relative;
            transform: scale(0.95); transition: transform 0.3s cubic-bezier(0.1, 0.9, 0.2, 1);
            border: 1px solid rgba(255, 255, 255, 0.6);
        }
        .modal-overlay.open .modal-content { transform: scale(1); }

        .close-btn {
            position: absolute; top: 20px; right: 20px; background: transparent;
            border: none; width: 36px; height: 36px; border-radius: 4px;
            cursor: pointer; display: flex; align-items: center; justify-content: center;
            color: #666; transition: 0.2s; z-index: 10;
        }
        .close-btn:hover { background: #e81123; color: white; }

        /* 网站分类 */
        .site-section { margin-bottom: 32px; }
        .section-title { 
            font-size: 16px; font-weight: 600; margin-bottom: 16px; 
            color: var(--text-main); display: flex; align-items: center;
        }
        .section-title::before {
            content: ''; display: inline-block; width: 4px; height: 18px;
            background: var(--accent); border-radius: 2px; margin-right: 12px;
        }

        /* 网站图标网格 */
        .site-grid { 
            display: grid; 
            grid-template-columns: repeat(auto-fill, minmax(110px, 1fr)); 
            gap: 10px; 
        }
        .site-card {
            display: flex; flex-direction: column; align-items: center; justify-content: center;
            gap: 6px; 
            padding: 12px 4px; 
            background: transparent; border-radius: 8px; 
            text-decoration: none; color: var(--text-main); font-size: 13px; transition: 0.2s;
        }
        .site-card:hover { background: rgba(0,0,0,0.05); transform: translateY(-2px); }
        .site-card img { width: 32px; height: 32px; border-radius: 6px; object-fit: contain; }
        .site-card .icon-placeholder { width: 32px; height: 32px; border-radius: 6px; }

        /* 滚动条美化 */
        .modal-content::-webkit-scrollbar { width: 6px; }
        .modal-content::-webkit-scrollbar-track { background: transparent; }
        .modal-content::-webkit-scrollbar-thumb { background: #d0d0d0; border-radius: 10px; }

        .footer {
            margin-top: auto; 
            padding: 30px 0 20px;
            color: var(--text-sub);
            font-size: 12px;
            text-align: center;
            width: 100%;
            opacity: 0.7;
            transition: opacity 0.2s;
        }

        .footer:hover { opacity: 1; }
        .footer a { color: var(--text-sub); text-decoration: none; margin: 0 8px; }
        .footer a:hover { color: var(--accent); text-decoration: underline; }

        /* Responsive */
        @media (max-width: 768px) {
            body { flex-direction: column; }
            .sidebar { display: none; }
            .main-content { order: 1; padding: 20px 20px 0 20px; }
            header { padding: 15px !important; }
            .center-container { margin-top: 10vh; }
            .modal-content { width: 100%; height: 100%; max-height: 100%; border-radius: 0; padding: 60px 20px 20px; }
            .site-grid { grid-template-columns: repeat(4, 1fr); }
            .quick-links { grid-template-columns: repeat(4, 1fr); gap: 10px; padding: 0; }
        }