/* roulang page: index */
:root {
            --primary: #0ea5e9;
            --primary-dark: #0284c7;
            --dark-surface: #0b0f19;
            --dark-card: #111827;
            --light-bg: #f8fafc;
            --border-color: #e2e8f0;
            --text-main: #0f172a;
            --text-muted: #64748b;
        }
        html { scroll-behavior: smooth; font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif; }
        body { background-color: var(--light-bg); color: var(--text-main); line-height: 1.75; }
        .hero-diagonal {
            clip-path: polygon(0 0, 100% 0, 100% 92%, 0 100%);
        }
        @media (max-width: 768px) {
            .hero-diagonal { clip-path: none; }
        }