#overlay {
  bottom: 0;
  left: 0;
  opacity: 0;
  overflow-y: auto;
  position: fixed;
  right: 0;
  text-align: center;
  top: 0;
  @include transition-property(opacity);
  @include transition-duration(0.2s);
  visibility: hidden;
  z-index: 1000;
}