/* roulang page: index */
:root {
            --bg-obsidian: #0b0d12;
            --bg-titanium: #12161f;
            --bg-card: #181d28;
            --cyber-purple: #7928ca;
            --neon-cyan: #00dfd8;
            --magma-orange: #ff5e3a;
            --text-pure: #f3f4f6;
            --text-muted: #9ca3af;
            --text-dim: #6b7280;
            --border-glow: rgba(255, 255, 255, 0.08);
            --shadow-glow: 0 0 25px -5px rgba(0, 223, 216, 0.15);
        }

        * {
            box-sizing: border-box;
            margin: 0;
            padding: 0;
        }

        body {
            background-color: var(--bg-obsidian);
            color: var(--text-pure);
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            line-height: 1.75;
            overflow-x: hidden;
        }

        .gradient-brand {
            background: linear-gradient(135deg, var(--cyber-purple) 0%, var(--neon-cyan) 100%);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }

        .border-glass {
            border: 1px solid var(--border-glow);
        }

        .glow-box {
            box-shadow: var(--shadow-glow);
        }

        .cta-btn {
            background: linear-gradient(135deg, var(--magma-orange) 0%, #ff8359 100%);
            transition: all 0.25s ease-out;
            min-height: 44px;
            min-width: 44px;
            display: inline-flex;
            align-items: center;
            justify-content: center;
        }
        .cta-btn:hover {
            transform: translateY(-2px);
            box-shadow: 0 8px 20px rgba(255, 94, 58, 0.35);
        }

        .secondary-btn {
            background: rgba(255, 255, 255, 0.05);
            border: 1px solid rgba(255, 255, 255, 0.15);
            transition: all 0.25s ease-out;
            min-height: 44px;
            min-width: 44px;
            display: inline-flex;
            align-items: center;
            justify-content: center;
        }
        .secondary-btn:hover {
            background: rgba(255, 255, 255, 0.12);
            border-color: var(--neon-cyan);
            color: var(--neon-cyan);
            transform: translateY(-2px);
        }

        .card-panel {
            background-color: var(--bg-card);
            border: 1px solid var(--border-glow);
            border-radius: 12px;
            transition: all 0.25s ease-out;
        }
        .card-panel:hover {
            border-color: rgba(0, 223, 216, 0.3);
            transform: translateY(-2px);
            box-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);
        }

        summary::-webkit-details-marker {
            display: none;
        }