title: how can select a parent tag?
body: <p>i have a code like below:</p>
  
  <pre><code>&lt;nav id="mainNav" class=""&gt;
     &lt;div id="navContainer"&gt;
         &lt;div id="active"&gt;
             [ some list ]
         &lt;/div&gt;&lt;!-- #active --&gt;
     &lt;/div&gt;&lt;!-- #navContainer --&gt;
  &lt;/nav&gt;&lt;!-- #mainNav --&gt;
  </code></pre>
  
  <p>i want to change the background color of #mainNav when user hover on #active, but i dont know what to do. i did this and no results:</p>
  
  <pre><code>#active:hover #mainNav{
     background-color: #333;
  }
  </code></pre>
  
  <p>any idea?</p>