/* roulang page: index */
:root {
            --primary: #1D4ED8;
            --primary-dark: #1E40AF;
            --accent: #0D9488;
            --accent-cyan: #06B6D4;
            --bg-light: #F8FAFC;
            --text-main: #0F172A;
            --text-sub: #334155;
            --text-muted: #64748B;
            --border-color: #E2E8F0;
        }
        html {
            scroll-behavior: smooth;
        }
        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            color: var(--text-main);
            background-color: var(--bg-light);
            line-height: 1.6;
        }
        .hero-bg {
            background-image: linear-gradient(to right, rgba(15, 23, 42, 0.95), rgba(15, 23, 42, 0.82)), url('/assets/images/03699bb4bd86f661.jpg');
            background-size: cover;
            background-position: center;
        }
        .card-hover {
            transition: all 0.25s ease;
        }
        .card-hover:hover {
            transform: translateY(-4px);
            box-shadow: 0 16px 30px -8px rgba(15, 23, 42, 0.12);
        }
        details summary::-webkit-details-marker {
            display: none;
        }
        details[open] summary .arrow-icon {
            transform: rotate(180deg);
        }