title: Set style for element if other element is hidden in CSS
body: <p>I have a div (parent) that contains two children. I want to change color of first DIV if second DIV is hidden.</p>
  
  <pre><code>&lt;div class="parent"&gt;
    &lt;div class="col-lg-6" style="display: block;"&gt;
       11111111
    &lt;/div&gt;
    &lt;div id="xyz" class="col-lg-6" style="display: none;"&gt;
       222222
    &lt;/div&gt;
  &lt;/div&gt;
  </code></pre>
  
  <p>I've tried something like:</p>
  
  <pre><code>.parent div:first-child:not(#xyz[hidden]) {
    background: #00ff00;
  }
  </code></pre>
  
  <p>but it doesn't work. So, is it possible in CSS3?</p>