title: Can CSS attribute selectors for boolean attributes be written more concisely?
body: <p>I've read that HTML "<a href="http://www.whatwg.org/specs/web-apps/current-work/#boolean-attribute" rel="noreferrer">boolean attributes</a>" such as <em>readonly</em>, <em>disabled</em>, <em>required</em> (etc.) can either be blank or have a value of their name. And people seem to be using both styles (see <a href="https://stackoverflow.com/questions/7335974/how-should-boolean-attributes-be-written">How should boolean attributes be written?</a>)...</p>
  
  <p>So it seems that the best way to accommodate this is to write your CSS like:</p>
  
  <pre><code>input[readonly], input[readonly="readonly"] {
  }
  </code></pre>
  
  <p>(<a href="https://stackoverflow.com/a/19644231/1766230">https://stackoverflow.com/a/19644231/1766230</a>)</p>
  
  <p>But <strong>is there a more concise way to write this?</strong> Maybe using some CSS3 attribute selector magic? I've tried <code>input[readonly*=""]</code>, but without luck.</p>