/* roulang page: index */
:root {
            --brand-primary: #4F46E5;
            --brand-gradient: linear-gradient(135deg, #4F46E5 0%, #7C3AED 100%);
            --brand-accent: #06B6D4;
            --brand-success: #10B981;
            --bg-page: #F8FAFC;
            --text-heading: #0F172A;
            --text-body: #334155;
            --text-muted: #64748B;
            --border-radius-card: 24px;
        }

        body {
            background-color: var(--bg-page);
            color: var(--text-body);
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            -webkit-font-smoothing: antialiased;
        }

        .gradient-brand {
            background: var(--brand-gradient);
        }

        .text-gradient {
            background: var(--brand-gradient);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }

        .card-interactive {
            transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), box-shadow 0.3s cubic-bezier(0.16, 1, 0.3, 1);
        }
        .card-interactive:hover {
            transform: translateY(-4px);
            box-shadow: 0 24px 48px -12px rgba(79, 70, 229, 0.16);
        }

        .btn-shimmer {
            position: relative;
            overflow: hidden;
        }
        .btn-shimmer::after {
            content: '';
            position: absolute;
            top: -50%;
            left: -60%;
            width: 40%;
            height: 200%;
            background: linear-gradient(to right, transparent, rgba(255, 255, 255, 0.35), transparent);
            transform: rotate(30deg);
            transition: all 0.7s cubic-bezier(0.19, 1, 0.22, 1);
        }
        .btn-shimmer:hover::after {
            left: 120%;
        }

        /* 原生手风琴平滑旋转指示器 */
        details summary::-webkit-details-marker {
            display: none;
        }
        details[open] summary svg.chevron {
            transform: rotate(180deg);
        }
        details summary svg.chevron {
            transition: transform 0.25s ease;
        }

        /* 统一平滑滚动补丁 */
        html {
            scroll-padding-top: 110px;
        }