/* roulang page: index */
:root {
            --brand-cyan: #0EA5E9;
            --brand-orange: #F97316;
            --brand-emerald: #10B981;
            --brand-navy: #0F172A;
            --surface-bg: #F8FAFC;
            --card-border: #E2E8F0;
        }
        html {
            scroll-behavior: smooth;
        }
        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "Noto Sans", sans-serif;
            background-color: var(--surface-bg);
            color: #1E293B;
            line-height: 1.6;
        }
        .hero-bg-overlay {
            background: linear-gradient(135deg, rgba(15, 23, 42, 0.88) 0%, rgba(14, 165, 233, 0.78) 55%, rgba(249, 115, 22, 0.75) 100%);
        }
        .text-gradient {
            background: linear-gradient(90deg, #0EA5E9 0%, #F97316 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }
        .card-custom {
            transition: all 0.28s ease;
            border: 1px solid var(--card-border);
        }
        .card-custom:hover {
            transform: translateY(-4px);
            box-shadow: 0 16px 30px -10px rgba(14, 165, 233, 0.15);
            border-color: #BAE6FD;
        }
        .glass-nav {
            backdrop-filter: blur(12px);
            -webkit-backdrop-filter: blur(12px);
            background-color: rgba(255, 255, 255, 0.94);
        }