/* roulang page: index */
:root {
            --bg-deep: #060B18;
            --bg-card: rgba(16, 29, 66, 0.65);
            --border-glow: rgba(0, 210, 255, 0.22);
            --cyan-core: #00D2FF;
            --green-core: #00F298;
        }
        body {
            background-color: var(--bg-deep);
            color: #E2E8F0;
            font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
            overflow-x: hidden;
        }
        .glass-card {
            background: var(--bg-card);
            backdrop-filter: blur(14px);
            -webkit-backdrop-filter: blur(14px);
            border: 1px solid var(--border-glow);
            transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1);
        }
        .glass-card:hover {
            border-color: rgba(0, 210, 255, 0.55);
            transform: translateY(-4px);
            box-shadow: 0 12px 30px -10px rgba(0, 210, 255, 0.25);
        }
        .glow-btn-primary {
            background: linear-gradient(135deg, #00D2FF 0%, #0066FF 100%);
            box-shadow: 0 0 20px rgba(0, 210, 255, 0.35);
            transition: all 0.3s ease;
        }
        .glow-btn-primary:hover {
            box-shadow: 0 0 30px rgba(0, 210, 255, 0.65);
            transform: translateY(-1px);
        }
        .glow-btn-secondary {
            background: rgba(16, 29, 66, 0.85);
            border: 1px solid rgba(0, 210, 255, 0.4);
            transition: all 0.3s ease;
        }
        .glow-btn-secondary:hover {
            background: rgba(0, 210, 255, 0.15);
            border-color: #00D2FF;
        }
        .topology-line {
            background: linear-gradient(90deg, rgba(0,210,255,0.1) 0%, rgba(0,210,255,0.8) 50%, rgba(0,242,152,0.1) 100%);
        }
        .text-glow {
            text-shadow: 0 0 16px rgba(0, 210, 255, 0.4);
        }
        /* 手风琴平滑过度 */
        .accordion-content {
            transition: max-height 0.3s ease-out, opacity 0.3s ease-out;
            max-height: 0;
            opacity: 0;
            overflow: hidden;
        }
        .accordion-content.open {
            max-height: 400px;
            opacity: 1;
        }
        .accordion-icon {
            transition: transform 0.3s ease;
        }
        .accordion-icon.open {
            transform: rotate(45deg);
        }