title: css issue on firefox, border not show correctly
body: <p>i got an issue on firefox, while all IE, Safari and chrome are working.</p>
  
  <pre><code>&lt;div class="forDiv"&gt;ddd&lt;/div&gt;
  &lt;table class="forTable"&gt; .... &lt;/table&gt;
  
  
  .forDiv {
  width:100%;
  border:3px solid #236FBD;
  background-color: #236FBD;
  }
  
  .forTable{
  width:100%;
  border:3px solid #236FBD;
  background-color: #236FBD;
  }
  </code></pre>
  
  <p>in firefox, the div is a bit smaller. how can i fix it?</p>