/* roulang page: index */
:root {
            --bg-primary: #0a0f1d;
            --bg-secondary: #0f172a;
            --accent-blue: #2563eb;
            --accent-cyan: #06b6d4;
            --neon-blue: #38bdf8;
            --amber-glow: #f59e0b;
            --text-main: #f8fafc;
            --text-sub: #cbd5e1;
            --text-muted: #64748b;
        }

        body {
            background-color: var(--bg-primary);
            color: var(--text-sub);
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            overflow-x: hidden;
        }

        .glass-card {
            background: rgba(30, 41, 59, 0.6);
            backdrop-filter: blur(12px);
            -webkit-backdrop-filter: blur(12px);
            border: 1px solid rgba(255, 255, 255, 0.08);
            box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.36), 0 0 15px rgba(37, 99, 235, 0.12);
        }

        .glass-card-hover {
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }

        .glass-card-hover:hover {
            transform: translateY(-4px);
            border-color: rgba(56, 189, 248, 0.3);
            box-shadow: 0 12px 40px 0 rgba(0, 0, 0, 0.45), 0 0 25px rgba(56, 189, 248, 0.2);
        }

        .btn-glow {
            background: linear-gradient(135deg, #2563eb 0%, #06b6d4 100%);
            box-shadow: 0 0 20px rgba(37, 99, 235, 0.5);
            transition: all 0.3s ease;
        }

        .btn-glow:hover {
            box-shadow: 0 0 28px rgba(6, 182, 212, 0.7);
            transform: translateY(-2px);
        }

        .text-gradient {
            background: linear-gradient(135deg, #f8fafc 0%, #38bdf8 50%, #06b6d4 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }

        .bg-grid-pattern {
            background-image: radial-gradient(rgba(56, 189, 248, 0.08) 1px, transparent 1px);
            background-size: 32px 32px;
        }

        /* Accordion transition */
        .faq-answer {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.35s ease-out;
        }
        .faq-item.active .faq-answer {
            max-height: 240px;
        }
        .faq-item.active .faq-icon {
            transform: rotate(180deg);
        }