/* roulang page: index */
:root {
            --primary: #0F172A;
            --brand-blue: #2563EB;
            --brand-cyan: #0EA5E9;
            --brand-green: #10B981;
            --bg-light: #F8FAFC;
            --text-main: #0F172A;
            --text-muted: #64748B;
            --border-color: #E2E8F0;
        }
        html {
            scroll-behavior: smooth;
            font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", "Noto Sans SC", sans-serif;
        }
        body {
            background-color: #F8FAFC;
            color: #334155;
            line-height: 1.75;
            box-sizing: border-box;
        }
        .hero-pattern {
            background: linear-gradient(135deg, rgba(15, 23, 42, 0.95), rgba(11, 15, 25, 0.92)), url('/assets/images/25943f9e0b57d125.png') center/cover no-repeat;
        }
        .deep-band {
            background: linear-gradient(180deg, #0B0F19 0%, #111827 100%), url('/assets/images/4d54b20d28f50c37.jpg') center/cover no-repeat;
        }
        .mesh-subtle {
            background-color: #FFFFFF;
            background-image: radial-gradient(#E2E8F0 1px, transparent 1px);
            background-size: 24px 24px;
        }
        .card-custom {
            background: #FFFFFF;
            border: 1px solid #E2E8F0;
            border-radius: 0.75rem;
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }
        .card-custom:hover {
            transform: translateY(-4px);
            box-shadow: 0 12px 24px -10px rgba(15, 23, 42, 0.12);
            border-color: #CBD5E1;
        }
        .btn-glow {
            position: relative;
            overflow: hidden;
            transition: all 0.3s ease;
        }
        .btn-glow:hover {
            box-shadow: 0 0 20px rgba(14, 165, 233, 0.45);
        }
        .tab-btn.active {
            background-color: #2563EB;
            color: #FFFFFF;
            border-color: #2563EB;
        }
        .custom-accordion-content {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.35s ease-out;
        }
        .custom-accordion-item.active .custom-accordion-content {
            max-height: 240px;
        }
        .custom-accordion-item.active .accordion-icon {
            transform: rotate(180deg);
        }