/* roulang page: index */
:root {
            --primary: #0d9488;
            --primary-dark: #0369a1;
            --accent: #ea580c;
            --bg-light: #f8fafc;
            --text-main: #1e293b;
            --text-muted: #64748b;
            --card-radius: 1.25rem;
            --shadow-soft: 0 10px 30px -5px rgba(13, 148, 136, 0.08);
            --shadow-hover: 0 20px 35px -5px rgba(13, 148, 136, 0.16);
        }
        body {
            color: var(--text-main);
            background-color: var(--bg-light);
            font-family: system-ui, -apple-system, BlinkMacSystemFont, "PingFang SC", "Microsoft YaHei", sans-serif;
            line-height: 1.75;
            -webkit-font-smoothing: antialiased;
        }
        .gradient-brand {
            background: linear-gradient(135deg, #0d9488 0%, #0369a1 100%);
        }
        .gradient-dark {
            background: linear-gradient(135deg, #0f172a 0%, #082f49 100%);
        }
        .card-custom {
            border-radius: var(--card-radius);
            box-shadow: var(--shadow-soft);
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }
        .card-custom:hover {
            box-shadow: var(--shadow-hover);
            transform: translateY(-4px);
        }
        details summary::-webkit-details-marker {
            display: none;
        }
        details[open] summary svg {
            transform: rotate(180deg);
        }