/* roulang page: index */
:root {
            --brand-primary: #1E3A8A;
            --brand-accent: #0284C7;
            --brand-dark: #0F172A;
            --brand-text: #334155;
            --brand-muted: #64748B;
            --brand-border: #E2E8F0;
            --shadow-subtle: 0 10px 25px -5px rgba(15, 23, 42, 0.06), 0 8px 10px -6px rgba(15, 23, 42, 0.04);
            --shadow-lift: 0 20px 30px -10px rgba(15, 23, 42, 0.12), 0 10px 15px -5px rgba(15, 23, 42, 0.05);
        }
        body {
            font-family: system-ui, -apple-system, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            color: var(--brand-text);
            background-color: #F8FAFC;
            line-height: 1.7;
            overflow-x: hidden;
        }
        .custom-card {
            background: #FFFFFF;
            border: 1px solid var(--brand-border);
            border-radius: 12px;
            box-shadow: var(--shadow-subtle);
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }
        .custom-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-lift);
            border-color: #CBD5E1;
        }
        .hero-overlay {
            background: linear-gradient(135deg, rgba(15, 30, 74, 0.94) 0%, rgba(30, 58, 138, 0.85) 60%, rgba(2, 132, 199, 0.75) 100%);
        }
        .anchor-offset {
            scroll-margin-top: 90px;
        }
        details summary::-webkit-details-marker {
            display: none;
        }