@antv/x6-plugin-snapline/es/index.css

snapline plugin for X6

.x6-widget-snapline {
  position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  pointer-events: none;
}
.x6-widget-snapline-vertical,
.x6-widget-snapline-horizontal {
  stroke: #2ecc71;
  stroke-width: 1px;
}