Animate the CSS transition property within :after/:before pseudo-classes

Question

Is it possible to animate CSS pseudo-classes?

Say I have:

#foo:after {
    content: \'\';
    width: 200px;
    height: 200px;
    background: red;
          


        

Answer 1

It does not seem to work now, however according to the W3 specs you can apply transitions to pseudo-elements. Maybe some time in future…