title: pure css conditionally change background-color of body
body: <p>Is it possible in <em>pure</em> css to change the <code>background-color</code> of the <code>body</code> element depending of the id (or class) of the first div inside the <code>body</code> ?</p>
  
  <p>For instance :</p>
  
  <pre><code>&lt;body&gt; 
    // background-color is black
    &lt;div id="abc"&gt; ... &lt;/div&gt;
  &lt;/body&gt;
  
  
  &lt;body&gt; 
    // background-color is red
    &lt;div id="cde"&gt; ... &lt;/div&gt;
  &lt;/body&gt;
  </code></pre>