/* roulang page: index */
:root {
            --primary: #059669;
            --primary-dark: #047857;
            --secondary: #0f172a;
            --bg-light: #f8fafc;
            --text-main: #1e293b;
            --text-muted: #64748b;
        }
        html { scroll-behavior: smooth; }
        body { font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif; color: var(--text-main); }
        .hero-pattern {
            background-color: #0b1329;
            background-image: radial-gradient(#10b981 0.75px, transparent 0.75px), radial-gradient(#1e293b 0.75px, #0b1329 0.75px);
            background-size: 30px 30px;
            background-position: 0 0, 15px 15px;
        }
        .text-glow {
            text-shadow: 0 0 20px rgba(16, 185, 129, 0.4);
        }
        .accordion-content {
            transition: max-height 0.3s ease-out, opacity 0.3s ease;
        }