Reverse a CSS animation

Question

I did this: http://codepen.io/yayoni/pen/pgXoWY

And I want to reverse the animation when I click on the small button but what I did doesnt work and I don\'t understand w

Answer 1

Try:

@keyframes exampleux {
0%   
{
    background-color: green; left:0px; top:0px; /* You need to add this */
}

100% 
{
    background-color: red; left:0px; top:0px;
}
}