/* roulang page: index */
:root {
            --primary: #00D26A;
            --primary-hover: #00B85C;
            --secondary: #FF6B00;
            --bg-dark: #0F172A;
            --bg-deep: #0B0F19;
            --text-main: #0F172A;
            --text-muted: #64748B;
        }
        html { scroll-behavior: smooth; }
        body { font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", "Heiti SC", sans-serif; }
        .hero-bg {
            background-image: linear-gradient(to right, rgba(11, 15, 25, 0.95), rgba(15, 23, 42, 0.85)), url('/assets/images/e3f74a604906f9b4.webp');
            background-size: cover;
            background-position: center;
        }
        .concept-bg {
            background-image: linear-gradient(to bottom, rgba(11, 15, 25, 0.96), rgba(11, 15, 25, 0.96)), url('/assets/images/37c951cf2045572f.png');
            background-size: cover;
            background-position: center;
        }