#loader {
  position: fixed;
  top: 45%;
  left: 50%;
  width: 52px;
  height: 52px;
  margin: -26px 0 0 -26px;
  background: black url(/images/loader.gif) center center no-repeat;
  @include hidpi(1.5) {
    background: black url(/images/loader@2x.gif) center center no-repeat;
  }
  background-size: 36px;
  border-radius: 26px;
  opacity: 0.7;
  display: none;
}