/* roulang page: index */
:root {
            --color-primary: #4F46E5;
            --color-secondary: #06B6D4;
            --color-accent: #F97316;
            --color-dark: #0F172A;
            --color-light: #F8FAFC;
        }
        html {
            scroll-behavior: smooth;
        }
        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            background-color: #F8FAFC;
            color: #1E293B;
            overflow-x: hidden;
        }
        .nav-gradient {
            background: linear-gradient(135deg, #1E1B4B 0%, #312E81 50%, #4338CA 100%);
        }
        .hero-overlay {
            background: linear-gradient(135deg, rgba(15, 23, 42, 0.92) 0%, rgba(30, 27, 75, 0.88) 60%, rgba(6, 182, 212, 0.75) 100%);
        }
        .code-tag {
            background: rgba(99, 102, 241, 0.12);
            color: #4F46E5;
            border: 1px solid rgba(99, 102, 241, 0.25);
        }
        .service-card:hover {
            transform: translateY(-4px);
        }
        details summary::-webkit-details-marker {
            display: none;
        }