title: Focus selector in Sass
body: <p>I focus in the input field and need to change the color of an icon and border-bottom of that class. How do I do it in Sass? I have already tried: </p>
  
  <pre><code>input
   + .input-group-addon // this is icon class
     &amp;:focus
      border-bottom: solid 2px #004eff
  </code></pre>
  
  <p>However it does nothing. Could you please help me? This is what HTML looks like.</p>
  
  <pre><code>&lt;div class="form-group" class="col-md-offset-1 col-xl-offset-1  focus-icon"&gt;
        &lt;div class="input-group"&gt;
          &lt;div class="input-group-addon man-icon"&gt;&lt;/div&gt;
          &lt;input type="email" placeholder="Логин"  required&gt;
        &lt;/div&gt;
      &lt;/div&gt;
  </code></pre>