title: How to add :after :before on submit button?
body: <p>I am trying to add :after/:before element on a submit button, but it not working for me. </p>
  
  <p>Actually I need to add swipe(Sweep To Right) transition effect on the button from left to right. Like - <a href="https://ianlunn.github.io/Hover/" rel="nofollow noreferrer">https://ianlunn.github.io/Hover/</a></p>
  
  <pre><code>&lt;input class="submitBtn" type="submit" name="" value="Submit"&gt;
  </code></pre>
  
  <pre><code>.submitBtn{ position: relative; width: 100%; height: 50px; background: #000; text-align: center; color: #FFF; border: none;}
  .submitBtn:after{ content: ''; position: absolute; width: 100%; height: 100%; background: yellow; left: 0; top: 0;}
  </code></pre>