/* roulang page: index */
:root {
            --primary: #0F52BA;
            --secondary: #00A86B;
            --accent: #FF6B35;
            --bg-light: #F8FAFC;
            --text-main: #1E293B;
            --text-muted: #64748B;
        }
        html {
            scroll-behavior: smooth;
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
        }
        .custom-shadow {
            box-shadow: 0 4px 20px -2px rgba(15, 82, 186, 0.06);
        }
        .custom-shadow:hover {
            box-shadow: 0 12px 30px -4px rgba(15, 82, 186, 0.12);
        }
        .hero-bg-overlay {
            background: linear-gradient(135deg, rgba(10, 25, 47, 0.94) 0%, rgba(15, 82, 186, 0.85) 100%);
        }
        details > summary {
            list-style: none;
        }
        details > summary::-webkit-details-marker {
            display: none;
        }
        details[open] summary .arrow-icon {
            transform: rotate(180deg);
        }