orgchart.js/demo/multiple-layers/style.css

organization chart plugin based on ES6

.hidden {
  display: none;
}

.orgchart .drill-icon {
  transition: opacity .5s;
  opacity: 0;
  right: -10px;
  top: -10px;
  z-index: 2;
  color: rgba(68, 157, 68, 0.5);
  font-size: 24px;
  position: absolute;
}

.orgchart .drill-icon:hover {
  color: #449d44;
}

.orgchart .node:hover .drill-icon {
  opacity: 1;
}