Do the animation once, then do the animation backwards:
The animation-direction property is supported in Internet Explorer 10, Firefox, and Opera.
Safari and Chrome support an alternative, the -webkit-animation-direction property.
Note: The animation-direction property is not supported in Internet Explorer 9 and earlier versions.
The animation-direction property defines whether or not the animation should play in reverse on alternate cycles.
If the animation-direction value is "alternate", the animation will be played as normal every odd time (1,3,5,etc..) and backwards every even time (2,4,6,etc...).
Note: If the animation is set to played only once, this property will have no effect.
|normal||Default value. The animation should be played as normal||Play it »|
|alternate||The animation should play in reverse on alternate cycles||Play it »|
CSS3 tutorial: CSS3 Animations
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