title: CSS styles doesn't apply when using ngClass
body: <p>I have a problem with dynamically CSS updating. This is my HTML code:</p>
  
  <pre><code>&lt;!DOCTYPE html&gt;
  &lt;html lang="en" ng-app="ListItems"&gt;
  &lt;head&gt;
      &lt;meta charset="utf-8"&gt;
      &lt;title&gt;Test project&lt;/title&gt;
      &lt;link rel="stylesheet" href="Content/bootstrap.css"&gt;
      &lt;link rel="stylesheet" href="Content/style.css"&gt;
  &lt;/head&gt;
  &lt;body ng-controller="ListController as list"&gt;
      &lt;h1&gt;To-do list&lt;/h1&gt;
  
      &lt;div id="main"&gt;
          &lt;article ng-repeat="item in items track by $index" ng-class="{{item.IsCompleted ? 'completed' : 'uncompleted'}}"&gt;
              &lt;p&gt;{{item.Description}}&lt;/p&gt;
              &lt;footer&gt;
                  &lt;small&gt;
                      Is completed: &lt;input type="checkbox" ng-checked="{{item.IsCompleted}}" ng-click="complete($index)" /&gt;
                  &lt;/small&gt;
              &lt;/footer&gt;
          &lt;/article&gt;
      &lt;/div&gt;
  
      &lt;script src="Scripts/angular.js"&gt;&lt;/script&gt;
      &lt;script src="Scripts/jquery-3.1.1.js"&gt;&lt;/script&gt;
      &lt;script src="Scripts/script.js"&gt;&lt;/script&gt;
  &lt;/body&gt;
  &lt;/html&gt;
  </code></pre>
  
  <p>And now I want to apply the following css styles if item is completed:</p>
  
  <pre><code>.completed {
      background-color: red;
  }
  </code></pre>
  
  <p>But nothing happened. </p>