/* roulang page: index */
:root {
            --bg-base: #090D16;
            --bg-sec: #0D1527;
            --primary-blue: #00D2FF;
            --accent-blue: #0066FF;
            --safety-green: #10B981;
            --text-main: #F8FAFC;
            --text-muted: #94A3B8;
            --border-glass: rgba(255, 255, 255, 0.08);
            --card-glass: rgba(15, 23, 42, 0.72);
        }
        * {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
            scroll-behavior: smooth;
        }
        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            background-color: var(--bg-base);
            color: var(--text-main);
            line-height: 1.6;
            overflow-x: hidden;
        }
        .glass-card {
            background: var(--card-glass);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            border: 1px solid var(--border-glass);
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }
        .glass-card:hover {
            border-color: rgba(0, 210, 255, 0.35);
            box-shadow: 0 10px 30px -10px rgba(0, 210, 255, 0.15);
            transform: translateY(-2px);
        }
        .btn-glow {
            background: linear-gradient(135deg, #00D2FF 0%, #0066FF 100%);
            box-shadow: 0 0 20px rgba(0, 210, 255, 0.45);
            transition: all 0.3s ease;
        }
        .btn-glow:hover {
            box-shadow: 0 0 30px rgba(0, 210, 255, 0.75);
            transform: scale(1.02);
        }
        .btn-secondary {
            background: rgba(255, 255, 255, 0.05);
            border: 1px solid rgba(0, 210, 255, 0.4);
            color: #F8FAFC;
            transition: all 0.3s ease;
        }
        .btn-secondary:hover {
            background: rgba(0, 210, 255, 0.15);
            border-color: #00D2FF;
        }
        .text-gradient {
            background: linear-gradient(135deg, #FFFFFF 20%, #00D2FF 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }
        .text-gradient-cyan {
            background: linear-gradient(135deg, #00D2FF 0%, #10B981 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }
        .glow-border {
            border: 1px solid rgba(0, 210, 255, 0.6);
            box-shadow: 0 0 25px rgba(0, 210, 255, 0.25);
        }
        .faq-content {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.35s ease-out;
        }
        .faq-item.active .faq-content {
            max-height: 240px;
        }
        .faq-item.active .faq-icon {
            transform: rotate(180deg);
        }