Create a "pop-out" icon for a photo gallery

icon.scss

.pop-out-icon {
  display: block;
  position: relative;
  
  &:after {
    @include pop-out;
    bottom: 1.5rem;
    content: "";
    position: absolute;
    right: 1.5rem;
    z-index: 2;
    
  }
}

pop-out.scss

@mixin pop-out {
  background-color: rgba(#000, .6);
  background-image: url("data:image/svg+xml;base64,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");
  background-position: 50% 50%;
  background-repeat: no-repeat;
  background-size: 1.6rem;
  border-radius: .4rem;
  display: block;
  height: 2.4rem;
  transition: background-color $animation-speed linear;
  width: 2.4rem;

  &:hover,
  &:active,
  &:focus {
    background-color: rgba(#000, .9);
  }
}