rc-adminlte/src/components/content/LoadingSpinner.css

AdminLTE template ported to React

.overlay,
.loading-img {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}
.overlay {
  z-index: 50;
  background: rgba(255, 255, 255, 0.7);
  border-radius: 3px;
}

.overlay > svg {
  position: absolute;
  top: 50%;
  left: 50%;
  margin-left: -15px;
  margin-top: -15px;
  color: #000;
}
.overlay.dark {
  background: rgba(0, 0, 0, 0.5);
}

.overlay {
  z-index: 50;
  background: rgba(255, 255, 255, 0.7);
  border-radius: 3px;
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

.overlay > .fa {
  position: absolute;
  top: 50%;
  left: 50%;
  margin-left: -15px;
  margin-top: -15px;
  color: #000;
  font-size: 30px;
}