Loading class

Append a class .loading to your element.

.any-element
  .loading

CSS for Background and Icon.

.loading {
  width: 100%;
  height: 100%;
  left: 0;
  top: 0;
  position: absolute;
  background: black;
  font-size: 20px;
  color: #antiquewhite;
  z-index: 99999;
  @include -opacity(0.8);

  &:after {
    content: "\f110";
    left: 50%;
    top: 50%;
    position: absolute;
    font-family: $font-awesome;

    animation: infinite-spin 2s linear infinite;
    -o-animation: infinite-spin 2s linear infinite;
    -ms-animation: infinite-spin 2s linear infinite;
    -moz-animation: infinite-spin 2s linear infinite;
    -webkit-animation: infinite-spin 2s linear infinite;
  }
}

@-moz-keyframes infinite-spin {
  from { -moz-transform: translate(-50%, -50%) rotate(0deg); }
  to { -moz-transform:  translate(-50%, -50%) rotate(360deg); }
}

@-webkit-keyframes infinite-spin {
  from { -webkit-transform: translate(-50%, -50%) rotate(0deg); }
  to { -webkit-transform: translate(-50%, -50%) rotate(360deg); }
}

@keyframes infinite-spin {
  from {transform: translate(-50%, -50%) rotate(0deg);}
  to {transform: translate(-50%, -50%) rotate(360deg);}
}