/* roulang page: index */
:root {
            --primary-navy: #0F172A;
            --slate-gray: #1E293B;
            --radar-cyan: #0EA5E9;
            --sensor-emerald: #059669;
            --amber-signal: #F59E0B;
            --card-border: rgba(226, 232, 240, 0.85);
            --bg-light: #F8FAFC;
            --deep-space: #0A0F1D;
        }

        body {
            font-family: system-ui, -apple-system, "PingFang SC", "Microsoft YaHei", sans-serif;
            background-color: var(--bg-light);
            color: #334155;
            line-height: 1.75;
            -webkit-font-smoothing: antialiased;
        }

        /* 工业级高精度网格装饰背景 */
        .aerial-grid-bg {
            background-color: #0c1322;
            background-image: 
                radial-gradient(circle at 50% 50%, rgba(14, 165, 233, 0.12) 0%, transparent 60%),
                linear-gradient(rgba(30, 41, 59, 0.35) 1px, transparent 1px),
                linear-gradient(90deg, rgba(30, 41, 59, 0.35) 1px, transparent 1px);
            background-size: 100% 100%, 32px 32px, 32px 32px;
        }

        .dark-tech-pattern {
            background-color: var(--deep-space);
            background-image: radial-gradient(rgba(14, 165, 233, 0.15) 1px, transparent 0);
            background-size: 24px 24px;
        }

        /* 微卡片悬浮动效 */
        .geo-card {
            background: #FFFFFF;
            border: 1px solid var(--card-border);
            box-shadow: 0 4px 20px -2px rgba(15, 23, 42, 0.04);
            transition: all 0.25s cubic-bezier(0.16, 1, 0.3, 1);
        }
        .geo-card:hover {
            transform: translateY(-3px);
            box-shadow: 0 12px 28px -4px rgba(14, 165, 233, 0.12);
            border-color: rgba(14, 165, 233, 0.4);
        }

        /* 航测光晕主按钮 */
        .btn-radar {
            background: linear-gradient(135deg, #0EA5E9 0%, #0284C7 100%);
            box-shadow: 0 4px 14px 0 rgba(14, 165, 233, 0.35);
            transition: all 0.2s ease;
        }
        .btn-radar:hover {
            box-shadow: 0 6px 20px 0 rgba(14, 165, 233, 0.5);
            transform: translateY(-1px);
        }

        /* 手风琴平滑高度动画 */
        .accordion-content {
            max-height: 0;
            overflow: hidden;
            transition: max-height 0.3s ease-out, opacity 0.25s ease-out;
            opacity: 0;
        }
        .accordion-content.open {
            opacity: 1;
        }

        /* 测绘标尺装饰线条 */
        .cad-crosshair {
            position: relative;
        }
        .cad-crosshair::before {
            content: "+";
            position: absolute;
            font-size: 12px;
            color: rgba(14, 165, 233, 0.5);
            font-family: monospace;
            top: -8px;
            left: -8px;
        }