@mixin flip($selector: ".flipped", $duration: 0.5s, $delay: 0s, $fill-mode: both, $count: 1, $timing: ease-in) {
  position: relative;
  @include u-prefix(transform-style, preserve-3d, webkit spec);
  @include u-transition(all $duration $delay $timing);
  @include u-prefix(backface-visibility, hidden, webkit moz spec);
  &#{$selector} {
    @include u-transform(rotateY(180deg)translateZ(0));
  }
  &::after {
    content: '';
    position: absolute;
    left: 0;
    height: 100%;
    width: 100%;
    @include u-prefix(backface-visibility, inherit, webkit moz spec);
    @include u-transform(rotateY(180deg));
  }
}

