title: CSS Transition on pseudo element did not work on Safari
body: <p>I try to create on hover hyperlink animation. When user hover on the link it will animate the underline. 
  I put the code here : <a href="http://codepen.io/elaelation/pen/bkicn" rel="nofollow">http://codepen.io/elaelation/pen/bkicn</a></p>
  
  <p>It works very well on Chrome &amp; Firefox, but it did not work on Safari. I already put the <code>-webkit-transition</code> for Safari bug, but it still didn't work.
  Is there anything wrong with my code ?</p>
  
  <p>thank you.</p>