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

In fact you don't need to use any CSS3 keyframes nor animation and use just transition: background-color 1s linear; to create the colour transition.

See you updated demo: http://codepen.io/anon/pen/YwozaQ