.loading {
  position: absolute;
  width: 100%;
  height: 100%;
  opacity: 0.6;
  background: black;
  top: 0;
  left: 0;
  z-index: 1005;
  md-spinner {
    margin-top: calc((100vh - 100px) / 2);
    margin-left: calc((100% - 100px) / 2);
  }
}