title: How to use border with Bootstrap
body: <p>How can I solve this problem?
  When you add borders to a div, the div is not centered and
  the <code>span12</code> class is not centered.</p>
  
  <p>I would like to center the div with the borders</p>
  
  <pre><code>&lt;div class="row" &gt;
     &lt;div class="span12" style="border: 2px solid black"&gt;
        &lt;div class="row"&gt;
           &lt;div class="span4"&gt;
              1
           &lt;/div&gt;
           &lt;div class="span4"&gt;
              2
           &lt;/div&gt;
           &lt;div class="span4"&gt;
              3
           &lt;/div&gt;
        &lt;/div&gt;
     &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>