div.loader {
  border-radius: 50%;
  width: 3em;
  height: 3em;
  position: fixed;
  left: 50%;
  margin-top: -1.25em;
  margin-left: -1.25em;
  background-color: white;
  z-index: 2050;
  box-shadow: 0 1px 6px 0 rgba(0, 0, 0, 0.12), 0 1px 6px 0 rgba(0, 0, 0, 0.12);
  
  text-align: center;
  
  top: 11em;
  opacity: 1.0;
  transition: opacity 200ms ease-out;
}

div.loader > i {
  line-height: 1.5em;
  margin-left: 0;
  margin-right: 0;
}

div.loader.loader-hidden {
  top: -4em;
  opacity: 0.0;
  transition: opacity 200ms ease-out;
}