body {
  font: 13px sans-serif;
  position: relative;
  width: 960px;
  height: 500px;
}

.node {
  fill: #000;
  cursor: crosshair;
}

.node.invisible {
    display: none;
}

.node_selected {
  fill: #ff7f0e;
  stroke: #ff7f0e;
}

.drag_line {
  stroke: #999;
  stroke-width: 5;
  pointer-events: none;
}

.drag_line_hidden {
  stroke: #999;
  stroke-width: 0;
  pointer-events: none;
}

.link {
  stroke: #999;
  stroke-width: 5;
  cursor: crosshair;
}

.link_selected {
  stroke: #ff7f0e;
}