math_panel.css

.panel.math .nodes > .unreferenced.content-node {
  display: none;
}

.show-unreferenced-math {
  position: fixed;
  display: block;
  right: 0px;
  font-size: 12px;
  font-weight: 600;
  top: 0px;
  padding-right: 15px;
  line-height: 40px;
  z-index: 60000;
  color: rgba(0,0,0,0.4);
}

.show-unreferenced-math.active {
  color: rgba(0,0,0, 1);
}

.show-unreferenced-math .fa-check-square-o {
  display: none;
}

.show-unreferenced-math.active .fa-square-o {
  display: none;
}

.show-unreferenced-math.active .fa-check-square-o {
  display: inline;
}

.show-unreferenced-math:hover {
  color: rgba(0,0,0, 0.7);
}