title: How to select first and last <th> only?
body: <p>My table has <code>id="mytable"</code>. I'm trying to apply some CSS on the first and last <code>&lt;th&gt;</code> only. I tried this but it doesn't work.</p>
  
  <pre><code>#mytable th:first,
  #mytable th:last{
   //css goes here
  }
  </code></pre>