/* roulang page: index */
:root {
            --primary-navy: #0F172A;
            --speed-blue: #2563EB;
            --speed-cyan: #06B6D4;
            --energy-green: #10B981;
            --bg-light: #F8FAFC;
            --text-main: #1E293B;
            --text-muted: #64748B;
            --border-color: rgba(226, 232, 240, 0.9);
            --gradient-brand: linear-gradient(135deg, #2563EB 0%, #06B6D4 100%);
        }
        
        body {
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
            background-color: var(--bg-light);
            color: var(--text-main);
            overflow-x: hidden;
            scroll-behavior: smooth;
        }

        .brand-gradient-bg {
            background: var(--gradient-brand);
        }

        .brand-gradient-text {
            background: var(--gradient-brand);
            -webkit-background-clip: text;
            -webkit-text-fill-color: transparent;
        }

        .nav-link {
            transition: color 0.2s ease-in-out;
        }
        .nav-link:hover {
            color: var(--speed-blue);
        }

        .feature-card {
            border: 1px solid var(--border-color);
            transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
        }
        .feature-card:hover {
            transform: translateY(-4px);
            box-shadow: 0 20px 25px -5px rgba(37, 99, 235, 0.1), 0 10px 10px -5px rgba(37, 99, 235, 0.04);
            border-color: rgba(37, 99, 235, 0.4);
        }

        .pulse-indicator {
            box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7);
            animation: pulse-green 2s infinite;
        }

        @keyframes pulse-green {
            0% {
                transform: scale(0.95);
                box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.7);
            }
            70% {
                transform: scale(1);
                box-shadow: 0 0 0 8px rgba(16, 185, 129, 0);
            }
            100% {
                transform: scale(0.95);
                box-shadow: 0 0 0 0 rgba(16, 185, 129, 0);
            }
        }

        details > summary {
            list-style: none;
        }
        details > summary::-webkit-details-marker {
            display: none;
        }