悬停时反转关键帧动画

这是一个演示：

http://codepen.io/Tiger0915/pen/GgjVLN http://codepen.io/Tiger0915/pen/GgjVLN

我有一个keyframe动画开启hover of the .circle分区当您将鼠标悬停在其上时，它可以正常工作。

@include keyframes(bounce-bulge) {
  0% {
    transform: scale(1);
  }
  20% {
    transform: scale(.75);
  }
  80% {
    transform: scale(1.75);
  }
  100% {
    transform: scale(1.5);
  }
}


.circle {
  transition: all 300ms ease;

  &:hover {
    @include animation(bounce-bulge 500ms forwards);
  }
}

我想扭转效果keyframe每当您停止将鼠标悬停在元素上时。

只用 CSS 就可以做到这一点吗？

看看我的例子，如果这是正确的你想要的（有人会发明更优雅的解决方案）

http://codepen.io/Mardzis/pen/YPGmmq http://codepen.io/Mardzis/pen/YPGmmq

CSS（SASS）：

@include keyframes(bounce-bulge) {
  0% {
    transform: scale(1);
  }
  20% {
    transform: scale(.75);
  }
  80% {
    transform: scale(1.75);
  }
  100% {
    transform: scale(1.5);
  }
}

@include keyframes(bounce-bulge-back) {
  100% {
    transform: scale(1);
  }
  80% {
    transform: scale(.75);
  }
  20% {
    transform: scale(1.75);
  }
  0% {
    transform: scale(1.5);
  }
}


.circle {
  margin: 100px auto 0;
  width: 30px;
  height: 30px;

  border: 10px solid blue;
  border-radius: 50%;
  background: lightblue;
  cursor: pointer;

  transition: all 300ms ease;
  @include animation(bounce-bulge-back 500ms forwards);

  &:hover {
    @include animation(bounce-bulge 500ms forwards);
  }
}