/* roulang page: index */
:root {
            --bg-deep: #0A0E1A;
            --card-bg: rgba(16, 24, 40, 0.85);
            --glass-border: rgba(255, 255, 255, 0.06);
            --primary-red: #FF3D2E;
            --accent-cyan: #00E5FF;
            --text-main: #F0F2F5;
            --text-secondary: #A0A7B8;
            --text-muted: #6B7280;
            --shadow-card: 0 12px 32px rgba(0, 0, 0, 0.6);
            --radius-lg: 20px;
            --radius-md: 14px;
            --radius-sm: 10px;
            --transition: all 0.25s ease;
            --nav-width: 260px;
            --font-sans: "PingFang SC", "Microsoft YaHei", "Helvetica Neue", sans-serif;
            --font-mono: "SF Mono", "Cascadia Code", "Consolas", monospace;
        }

        * {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }

        body {
            font-family: var(--font-sans);
            background-color: var(--bg-deep);
            color: var(--text-main);
            line-height: 1.7;
            font-size: 16px;
            -webkit-font-smoothing: antialiased;
            display: flex;
            flex-direction: row;
            min-height: 100vh;
            overflow-x: hidden;
        }

        img {
            max-width: 100%;
            height: auto;
            display: block;
        }

        a {
            text-decoration: none;
            color: inherit;
            transition: var(--transition);
        }

        .btn {
            display: inline-flex;
            align-items: center;
            justify-content: center;
            gap: 0.5rem;
            font-weight: 600;
            border-radius: 40px;
            padding: 0.8rem 2rem;
            font-size: 1rem;
            letter-spacing: 0.3px;
            cursor: pointer;
            transition: var(--transition);
            border: none;
            white-space: nowrap;
        }

        .btn-primary {
            background: var(--primary-red);
            color: white;
            box-shadow: 0 8px 20px rgba(255, 61, 46, 0.35);
        }

        .btn-primary:hover {
            background: #e62e1f;
            box-shadow: 0 0 28px rgba(255, 61, 46, 0.7);
            transform: translateY(-2px);
        }

        .btn-ghost {
            background: transparent;
            border: 1px solid rgba(255, 255, 255, 0.25);
            color: white;
            backdrop-filter: blur(8px);
        }

        .btn-ghost:hover {
            border-color: var(--accent-cyan);
            color: var(--accent-cyan);
            box-shadow: 0 0 16px rgba(0, 229, 255, 0.3);
        }

        /* 左侧导航桌面 */
        .side-nav {
            width: var(--nav-width);
            height: 100vh;
            position: fixed;
            left: 0;
            top: 0;
            background: rgba(8, 14, 24, 0.9);
            backdrop-filter: blur(28px);
            -webkit-backdrop-filter: blur(28px);
            border-right: 1px solid var(--glass-border);
            display: flex;
            flex-direction: column;
            padding: 2rem 1.2rem;
            z-index: 50;
            box-shadow: 4px 0 25px rgba(0,0,0,0.7);
        }

        .logo-area {
            display: flex;
            align-items: center;
            gap: 10px;
            margin-bottom: 3rem;
            font-weight: 700;
            font-size: 1.5rem;
            color: white;
        }
        .logo-icon {
            font-size: 2rem;
            color: var(--primary-red);
        }

        .nav-links {
            list-style: none;
            display: flex;
            flex-direction: column;
            gap: 1.2rem;
        }

        .nav-links li a {
            display: flex;
            align-items: center;
            gap: 0.8rem;
            color: var(--text-secondary);
            font-weight: 500;
            padding: 0.55rem 1rem;
            border-radius: 30px;
            transition: var(--transition);
            position: relative;
        }

        .nav-links li a i {
            width: 20px;
            text-align: center;
        }

        .nav-links li a:hover,
        .nav-links li a.active {
            color: white;
            background: rgba(255, 255, 255, 0.05);
        }

        .nav-links li a.active::before {
            content: '';
            position: absolute;
            left: -8px;
            top: 12px;
            bottom: 12px;
            width: 4px;
            background: var(--accent-cyan);
            border-radius: 4px;
        }

        /* 右侧主内容 */
        .main-content {
            margin-left: var(--nav-width);
            width: calc(100% - var(--nav-width));
            background: var(--bg-deep);
        }

        .container-custom {
            max-width: 1280px;
            margin: 0 auto;
            padding: 0 2.5rem;
        }

        section {
            padding: 5rem 0;
        }

        h2 {
            font-size: 2.2rem;
            font-weight: 700;
            margin-bottom: 1rem;
            color: white;
            letter-spacing: -0.3px;
        }

        .section-sub {
            color: var(--text-secondary);
            font-size: 1.1rem;
            margin-bottom: 2.5rem;
        }

        /* 移动端顶部导航 */
        .mobile-header {
            display: none;
        }

        @media screen and (max-width: 1024px) {
            body {
                flex-direction: column;
            }
            .side-nav {
                display: none;
            }
            .main-content {
                margin-left: 0;
                width: 100%;
            }
            .mobile-header {
                display: flex;
                align-items: center;
                justify-content: space-between;
                padding: 1rem 1.8rem;
                background: rgba(8, 14, 24, 0.95);
                backdrop-filter: blur(20px);
                position: sticky;
                top: 0;
                z-index: 45;
                border-bottom: 1px solid var(--glass-border);
            }
            .mobile-logo {
                display: flex;
                align-items: center;
                gap: 8px;
                font-weight: 700;
                font-size: 1.4rem;
                color: white;
            }
            .hamburger {
                font-size: 1.8rem;
                color: white;
                cursor: pointer;
            }
        }

        /* 玻璃卡片通用 */
        .glass-card {
            background: var(--card-bg);
            backdrop-filter: blur(18px);
            -webkit-backdrop-filter: blur(18px);
            border: 1px solid var(--glass-border);
            border-radius: var(--radius-lg);
            box-shadow: var(--shadow-card);
            transition: var(--transition);
        }
        .glass-card:hover {
            border-color: rgba(0,229,255,0.25);
            transform: translateY(-5px);
            box-shadow: 0 20px 35px rgba(0,0,0,0.8);
        }

        .stat-number {
            font-family: var(--font-mono);
            font-weight: 700;
            font-size: 2.5rem;
            color: var(--primary-red);
            font-variant-numeric: tabular-nums;
        }