/* 蓝图连线专用类 */
#svg-layer { position: absolute; top: 0; left: 0; width: 100%; height: 100%; pointer-events: none; overflow: visible; z-index: 5; }
.connection-group { cursor: crosshair; outline: none; }
.connection-line-hit { fill: none; stroke: transparent; stroke-width: 18px; pointer-events: stroke; }
.connection-line-visual { fill: none; stroke: var(--border-deep); stroke-width: 3px; stroke-linecap: round; pointer-events: none; transition: stroke 0.3s, stroke-width 0.3s; }
.connection-group:hover .connection-line-visual { stroke: var(--danger) !important; stroke-width: 6px; }

/* 连线颜色变体 */
.connection-line-visual.line-init { stroke: var(--text-main); }
.connection-line-visual.line-tab { stroke: #3b82f6; }
.connection-line-visual.line-direct { stroke: var(--warning); }
.connection-line-visual.line-check { stroke: #a855f7; }