title: Horizontally center <span> inside <a>
body: <p>I want to horizontally center a span inside an a-tag. The problem is that I can't set the height nor the width of the span. My markups is as follows:</p>
  
  <pre><code>&lt;div class="footer"&gt;
       &lt;a href="#"&gt;
            &lt;span&gt;Show/Hide&lt;/span&gt;
       &lt;/a&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>And the css:</p>
  
  <pre><code>.footer {position:absolute; bottom:0; width:100%;}
  .footer a {display:block; background:orange; text-align:center;}
  .footer a span {background:#FFF; font-size:12px; width:100px;}
  </code></pre>
  
  <p>I've tried everything, but think I need some sort of float somewhere, but don't know. Help are gladly appreciated! :-)</p>