i would not recommend using @keyframes for this simple animation.
this article may help you
http://www.kirupa.com/html5/css3_animations_vs_transitions.htm
Conclusion There you have it - a candid look at what makes transitions
and animations similar yet so very different. My general approach for
determining when to use which goes like this:
If what I want requires the flexibility provided by having multiple
keyframes and easy looping, then I go with an animation. If I am
looking for a simple from/to animation, I go with a transition. If I
want to manipulate the property values that I wish to animate using
JavaScript, I go with a transition.
cause performance is a valuable thing .