title: div with display:inline-block margin 0 auto not center
body: <pre><code>&lt;div style="display: inline-block; margin: 0 auto;"&gt;
      &lt;input id="abc" type="button" value="button" /&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>I try to use the code above to set the width of  equal it's content, and then center it with margin: 0 auto;</p>
  
  <p>But it did not work for me on any browser. Any suggestion?</p>
  
  <p>BTW, when I set the width property, it works fine.</p>
  
  <pre><code>&lt;div style="width: 10em; margin: 0 auto;"&gt;
      &lt;input id="abc" type="button" value="button" /&gt;
  &lt;/div&gt;
  </code></pre>