/* roulang page: index */
:root {
            --bg-main: #0a0b0e;
            --bg-card: #12161f;
            --neon-cyan: #00f0ff;
            --neon-purple: #8a2be2;
            --neon-magenta: #ff007f;
            --text-main: #ffffff;
            --text-muted: #94a3b8;
            --border-dim: rgba(0, 240, 255, 0.15);
        }
        body {
            background-color: var(--bg-main);
            color: var(--text-main);
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            overflow-x: hidden;
        }
        .neon-border {
            border: 1px solid var(--border-dim);
            transition: all 0.3s ease;
        }
        .neon-border:hover {
            border-color: var(--neon-cyan);
            box-shadow: 0 0 20px rgba(0, 240, 255, 0.25);
        }
        .neon-glow-btn {
            background: linear-gradient(135deg, rgba(0,240,255,0.15) 0%, rgba(138,43,226,0.15) 100%);
            border: 1px solid var(--neon-cyan);
            box-shadow: 0 0 15px rgba(0, 240, 255, 0.2);
            transition: all 0.25s ease-in-out;
        }
        .neon-glow-btn:hover {
            background: var(--neon-cyan);
            color: #050608;
            box-shadow: 0 0 25px rgba(0, 240, 255, 0.6);
        }
        .text-glow {
            text-shadow: 0 0 12px rgba(0, 240, 255, 0.4);
        }
        .nav-link {
            position: relative;
        }
        .nav-link::after {
            content: '';
            position: absolute;
            width: 0;
            height: 2px;
            bottom: -4px;
            left: 0;
            background-color: var(--neon-cyan);
            box-shadow: 0 0 8px var(--neon-cyan);
            transition: width 0.3s;
        }
        .nav-link:hover::after, .nav-link.active::after {
            width: 100%;
        }
        details summary::-webkit-details-marker {
            display: none;
        }
        .section-separator {
            background: radial-gradient(circle, rgba(0,240,255,0.2) 0%, rgba(10,11,14,0) 70%);
            height: 1px;
            width: 100%;
        }