/* roulang page: index */
:root {
            --primary-blue: #1A56DB;
            --secondary-teal: #0D9488;
            --accent-orange: #F97316;
            --bg-canvas: #F8FAFC;
            --dark-card: #0F172A;
            --text-main: #0F172A;
            --text-muted: #64748B;
            --border-light: #E2E8F0;
        }

        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: var(--bg-canvas);
            color: var(--text-main);
            line-height: 1.75;
            -webkit-font-smoothing: antialiased;
        }

        .hero-overlay {
            background: linear-gradient(135deg, rgba(15, 23, 42, 0.88) 0%, rgba(26, 86, 219, 0.82) 100%);
        }

        .dark-section-bg {
            background-color: #0B1120;
            background-image: radial-gradient(at 0% 0%, rgba(26, 86, 219, 0.25) 0px, transparent 50%),
                              radial-gradient(at 100% 100%, rgba(13, 148, 136, 0.2) 0px, transparent 50%);
        }

        .card-custom {
            background: #FFFFFF;
            border: 1px solid var(--border-light);
            box-shadow: 0 1px 3px rgba(0, 0, 0, 0.04);
            transition: transform 0.25s ease, box-shadow 0.25s ease;
        }

        .card-custom:hover {
            transform: translateY(-4px);
            box-shadow: 0 12px 28px -6px rgba(26, 86, 219, 0.12);
        }

        .badge-subtle {
            display: inline-flex;
            align-items: center;
            padding: 0.25rem 0.75rem;
            border-radius: 9999px;
            font-size: 0.8125rem;
            font-weight: 600;
        }

        details > summary {
            list-style: none;
        }
        details > summary::-webkit-details-marker {
            display: none;
        }
        details[open] summary .faq-chevron {
            transform: rotate(180deg);
        }