title: Styling <a> without href attribute
body: <p>Is it possible to match all links without <code>href</code> specified via CSS?</p>
  
  <p>Example:</p>
  
  <pre><code>&lt;a&gt;Invalid link&lt;/a&gt;
  </code></pre>
  
  <p>I know its possible to match all links with href but I'm just looking for the opposite.</p>