not apply after in table-cell why?
===

Hi I m give to after in table-cell div but this is effective why ?

Please help me 

**Check to this in firefox**


My code is 

    <div class="parent">
      
    </div>

**Css**



    .parent{
      background:red;
      width:100px;
      height:100px;
      position:relative;
      display:table-cell;
    }
    
    .parent:after{
    left:0;
      content:'';
      right:0;
      top:10px;
      height:20px;
      background:green;
      position:absolute;
    }

[Live demo][1] 


  [1]: http://tinkerbin.com/9eEVN6Pj