/* roulang page: index */
:root {
            --brand-gradient: linear-gradient(135deg, #1D4ED8 0%, #0D9488 100%);
            --card-shadow: 0 4px 20px -2px rgba(15, 23, 42, 0.05);
            --card-shadow-hover: 0 20px 25px -5px rgba(37, 99, 235, 0.12), 0 8px 10px -6px rgba(37, 99, 235, 0.06);
        }
        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;
            color: #334155;
            background-color: #F8FAFC;
        }
        .brand-gradient-bg {
            background: var(--brand-gradient);
        }
        .brand-gradient-text {
            background: var(--brand-gradient);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }
        .card-soft {
            box-shadow: var(--card-shadow);
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }
        .card-soft:hover {
            box-shadow: var(--card-shadow-hover);
            transform: translateY(-4px);
        }
        details summary::-webkit-details-marker {
            display: none;
        }
        details[open] .faq-icon {
            transform: rotate(180deg);
        }