/* roulang page: index */
:root {
            --bg-main: #F8F9FA;
            --text-title: #0F172A;
            --text-body: #334155;
            --text-muted: #64748B;
            --color-cyan: #0EA5E9;
            --color-indigo: #6366F1;
            --border-soft: rgba(226, 232, 240, 0.8);
        }
        body {
            background-color: var(--bg-main);
            color: var(--text-body);
            font-family: 'PingFang SC', 'Noto Sans SC', 'Microsoft YaHei', 'Inter', sans-serif;
            -webkit-font-smoothing: antialiased;
        }
        .text-tight {
            letter-spacing: -0.02em;
        }
        .glass-nav {
            background: rgba(255, 255, 255, 0.92);
            backdrop-filter: blur(12px);
            border-bottom: 1px solid var(--border-soft);
        }
        .hero-mask {
            background: linear-gradient(135deg, rgba(11, 15, 25, 0.92) 0%, rgba(15, 23, 42, 0.82) 100%);
        }
        .card-subtle {
            background: #FFFFFF;
            border: 1px solid var(--border-soft);
            box-shadow: 0 8px 30px rgba(0, 0, 0, 0.04);
            transition: transform 0.2s ease, box-shadow 0.2s ease;
        }
        .card-subtle:hover {
            transform: translateY(-2px);
            box-shadow: 0 14px 36px rgba(0, 0, 0, 0.08);
        }
        .glow-effect {
            position: relative;
        }
        .glow-effect::before {
            content: '';
            position: absolute;
            top: 20%;
            left: 50%;
            width: 400px;
            height: 400px;
            background: radial-gradient(circle, rgba(14, 165, 233, 0.15) 0%, rgba(99, 102, 241, 0.05) 50%, transparent 70%);
            transform: translate(-50%, -50%);
            z-index: 0;
            pointer-events: none;
        }
        details > summary {
            list-style: none;
        }
        details > summary::-webkit-details-marker {
            display: none;
        }
        details[open] summary svg {
            transform: rotate(180deg);
        }