/* roulang page: index */
:root {
            --primary: #1D4ED8;
            --primary-hover: #1E40AF;
            --accent: #0284C7;
            --success: #10B981;
            --text-main: #0F172A;
            --text-sub: #475569;
            --bg-body: #F8FAFC;
            --border-color: #E2E8F0;
            --radius-card: 12px;
            --shadow-default: 0 1px 3px 0 rgba(15, 23, 42, 0.05), 0 1px 2px -1px rgba(15, 23, 42, 0.05);
            --shadow-hover: 0 12px 24px -4px rgba(29, 78, 216, 0.08);
        }
        
        * {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }

        html {
            scroll-behavior: smooth;
        }

        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            background-color: var(--bg-body);
            color: var(--text-main);
            line-height: 1.65;
            overflow-x: hidden;
        }

        .interactive-card {
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
            border: 1px solid var(--border-color);
            background-color: #FFFFFF;
            border-radius: var(--radius-card);
        }

        .interactive-card:hover {
            transform: translateY(-4px);
            box-shadow: var(--shadow-hover);
            border-color: #BFDBFE;
        }

        details > summary {
            list-style: none;
        }
        details > summary::-webkit-details-marker {
            display: none;
        }
        details[open] summary svg {
            transform: rotate(180deg);
        }

        .tap-area {
            min-height: 44px;
            min-width: 44px;
            display: inline-flex;
            align-items: center;
            justify-content: center;
        }