/* roulang page: index */
:root {
            --brand-primary: #1D4ED8;
            --brand-cyan: #06B6D4;
            --brand-dark: #0B0F19;
            --text-main: #0F172A;
            --text-body: #334155;
            --card-border: rgba(226, 232, 240, 0.85);
            --card-shadow: 0 20px 25px -5px rgba(15, 23, 42, 0.05), 0 8px 10px -6px rgba(15, 23, 42, 0.03);
        }
        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            color: var(--text-body);
            background-color: #F8FAFC;
        }
        .hud-glow {
            box-shadow: 0 0 50px -10px rgba(6, 182, 212, 0.25);
        }
        .btn-gradient {
            background: linear-gradient(135deg, #1D4ED8 0%, #06B6D4 100%);
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }
        .btn-gradient:hover {
            box-shadow: 0 10px 20px -5px rgba(29, 78, 216, 0.4);
            transform: translateY(-2px);
        }
        .card-surface {
            background: #FFFFFF;
            border: 1px solid var(--card-border);
            box-shadow: var(--card-shadow);
            transition: all 0.3s ease;
        }
        .card-surface:hover {
            transform: translateY(-4px);
            box-shadow: 0 25px 30px -5px rgba(15, 23, 42, 0.08), 0 10px 15px -5px rgba(6, 182, 212, 0.08);
            border-color: rgba(6, 182, 212, 0.4);
        }
        .dark-glass {
            background: rgba(15, 23, 42, 0.75);
            backdrop-filter: blur(16px);
            border: 1px solid rgba(255, 255, 255, 0.08);
        }
        .radar-ping {
            animation: radarPing 2.5s cubic-bezier(0, 0, 0.2, 1) infinite;
        }
        @keyframes radarPing {
            75%, 100% {
                transform: scale(2.2);
                opacity: 0;
            }
        }