.retina-border(@border: border, @color: #d7d7d7, @position: relative) {
  position: @position;
  &:after {
    content: '';
    transform: scale(0.5);
    transform-origin: 0 0;
    @{border}: 1px solid @color;
    width: 200%;
    height: 200%;
    position: absolute;
    left: 0;
    top: 0;
    pointer-events: none;
    box-sizing: border-box;
  }
}