title: How to change the border color of ngTagsInput with/without focus?
body: <p>Given this HTML that declares the tags-input directive:</p>
  
  <pre><code>&lt;tags-input class="bootstrap" ng-model="selected"&gt;
      &lt;auto-complete source="getList($query)"&gt;&lt;/auto-complete&gt;
  &lt;/tags-input&gt;
  </code></pre>
  
  <p>This CSS doesn't change the border to blue:</p>
  
  <pre><code>.bootstrap .tags {
    border: 1px solid blue;
  }
  </code></pre>
  
  <p>This CSS doesn't change the border to red when ngTagsInput gets the focus</p>
  
  <pre><code>.bootstrap .tags:focused {
    border-color: red;
  }
  </code></pre>