title: Bootstrap 3 grid custom class
body: <p>I'm using Bootstrap 3 to design a website, and I would like to ask how could I apply a custom class to an existing col-md-12 for example, so I won't use ids (#cusom-name) ?</p>
  
  <p>should I write my css like </p>
  
  <pre><code>.col-md-12 test {
      background: blue;
      padding-left: 10px;
  }
  </code></pre>
  
  <p>and my html like: </p>
  
  <pre><code>&lt;div class="col-md-12 test"&gt;div content&lt;/div&gt;
  </code></pre>
  
  <p>or should I just stick to something like using a standard col-md-12 and inside it use my custom class with a new div? like</p>
  
  <pre><code>&lt;div class="col-md-12"&gt;
      &lt;div class="test"&gt;
          test content
      &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>I hope it's clear enough... thanks!</p>