/* roulang page: index */
:root {
            --primary: #1d4ed8;
            --primary-hover: #1e40af;
            --accent: #0ea5e9;
            --bg-canvas: #f8fafc;
            --text-heading: #0f172a;
            --text-body: #475569;
            --text-muted: #94a3b8;
            --border-light: #e2e8f0;
            --card-shadow: 0 4px 20px -2px rgba(15, 23, 42, 0.05), 0 2px 6px -1px rgba(15, 23, 42, 0.03);
            --card-hover-shadow: 0 20px 30px -10px rgba(29, 78, 216, 0.12), 0 8px 12px -3px rgba(15, 23, 42, 0.06);
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            background-color: var(--bg-canvas);
            color: var(--text-body);
            line-height: 1.65;
            -webkit-font-smoothing: antialiased;
        }

        .custom-card {
            background: #ffffff;
            border: 1px solid var(--border-light);
            border-radius: 1rem;
            box-shadow: var(--card-shadow);
            transition: all 0.3s cubic-bezier(0.16, 1, 0.3, 1);
        }

        .custom-card:hover {
            transform: translateY(-5px);
            box-shadow: var(--card-hover-shadow);
            border-color: #cbd5e1;
        }

        .hero-gradient-overlay {
            background: linear-gradient(135deg, rgba(15, 23, 42, 0.88) 0%, rgba(30, 58, 138, 0.82) 50%, rgba(14, 165, 233, 0.7) 100%);
        }

        details summary::-webkit-details-marker {
            display: none;
        }

        details[open] summary .faq-icon {
            transform: rotate(180deg);
        }

        .cta-btn-glow {
            box-shadow: 0 0 20px rgba(14, 165, 233, 0.4);
        }

        .cta-btn-glow:hover {
            box-shadow: 0 0 30px rgba(14, 165, 233, 0.65);
        }