// Opacity

@mixin opacity($opacity) {
  opacity: $opacity;
  // IE8 filter
  $opacity-ie: ($opacity * 100);
  filter: #{alpha(opacity=$opacity-ie)};
}

@mixin black-filter($opacity) {
  top: 0;
  left: 0;
  height: 100%;
  width: 100%;
  position: absolute;
  background-color: rgba(17, 17, 17, $opacity);
  display: block;
  content: "";
  z-index: 1;
}