.loading {
    position: fixed;
    z-index: 1700;
    height: 2em;
    width: 2em;
    overflow: show;
    margin: auto;
    top: 0;
    left: 0;
    bottom: 0;
    right: 0;
}

/* Transparent Overlay */
.loading:before {
  content: '';
  display: block;
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background-color: rgba(0,0,0,0.3);
}

/* :not(:required) hides these rules from IE9 and below */
.loading:not(:required) {
  /* hide "loading..." text */
  font: 0/0 a;
  color: transparent;
  text-shadow: none;
  background-color: transparent;
  border: 0;
}