title: How to use if statements in LESS
body: <p>I'm looking for some kind of if-statement to control the <code>background-color</code> of different <code>div</code> elements.</p>
  
  <p>I have tried the below, but it doesn't compile</p>
  
  <pre><code>@debug: true;
  
  header {
    background-color: (yellow) when (@debug = true);
    #title {
        background-color: (orange) when (@debug = true);
    }
  }
  
  article {
    background-color: (red) when (@debug = true);
  }
  </code></pre>