title: when to leave space ,when not in CSS?
body: <p>This is ok(without space):</p>
  
  <pre><code>li.highlight{
      background:#FF9900 none repeat scroll 0 0;
  }
  </code></pre>
  
  <p>This will not work(with space):</p>
  
  <pre><code>li .highlight{
      background:#FF9900 none repeat scroll 0 0;
  }
  </code></pre>
  
  <p>Why?</p>