/* roulang page: index */
:root {
            --bg-deep: #0B132B;
            --bg-secondary: #1C2541;
            --card-glass: rgba(28, 37, 65, 0.72);
            --accent-cyan: #48CAE4;
            --accent-blue: #0077B6;
            --border-glow: rgba(72, 202, 228, 0.25);
            --text-main: #F8FAFC;
            --text-muted: #94A3B8;
        }
        html {
            scroll-behavior: smooth;
        }
        body {
            background-color: var(--bg-deep);
            color: var(--text-main);
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
            overflow-x: hidden;
        }
        .glass-card {
            background: var(--card-glass);
            backdrop-filter: blur(16px);
            -webkit-backdrop-filter: blur(16px);
            border: 1px solid rgba(255, 255, 255, 0.1);
            box-shadow: 0 8px 32px 0 rgba(0, 0, 0, 0.37);
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }
        .glass-card:hover {
            border-color: rgba(72, 202, 228, 0.4);
            transform: translateY(-4px);
            box-shadow: 0 12px 36px 0 rgba(0, 119, 182, 0.28);
        }
        .btn-glow {
            background: linear-gradient(135deg, #0077b6 0%, #00b4d8 100%);
            box-shadow: 0 0 20px rgba(0, 180, 216, 0.45);
            transition: all 0.3s ease;
        }
        .btn-glow:hover {
            box-shadow: 0 0 30px rgba(72, 202, 228, 0.75);
            transform: scale(1.02);
        }
        .btn-outline-glow {
            border: 1px solid var(--accent-cyan);
            color: var(--accent-cyan);
            transition: all 0.3s ease;
        }
        .btn-outline-glow:hover {
            background: rgba(72, 202, 228, 0.12);
            box-shadow: 0 0 18px rgba(72, 202, 228, 0.3);
            color: #fff;
        }
        .glow-text {
            text-shadow: 0 0 15px rgba(72, 202, 228, 0.5);
        }
        .glow-border-active {
            border: 1px solid var(--accent-cyan);
            box-shadow: 0 0 22px rgba(0, 180, 216, 0.35);
        }
        .section-separator {
            border-bottom: 1px solid rgba(255, 255, 255, 0.06);
        }
        details summary::-webkit-details-marker {
            display: none;
        }
        .tab-btn.active {
            background: #0077B6;
            color: #ffffff;
            border-color: #48CAE4;
            box-shadow: 0 0 16px rgba(72, 202, 228, 0.4);
        }