title: How to set the css of the li:before with ng-style
body: <p>I want to change the width value of the li:before with a  variable scope (width).</p>
  
  <pre><code> &lt;ul&gt;
      &lt;li ng-repeat="step in stepsList" ng-style="{li:before { 'width': width;}"
          ng-class="{true: 'active'}[step.active]"&gt;
          &lt;span&gt;{{step.stepName | uppercase}}&lt;/span&gt;
      &lt;/li&gt;
  &lt;/ul&gt;
  </code></pre>
  
  <p>I'm doing this code but it's not working.
  help please.</p>