title: sourceURL for CSS
body: <p>Is debugging <code>sourceURL</code> possible for CSS in Firefox?</p>
  <p>The solutions listed in the following do not appear to work:</p>
  <ul>
  <li><a href="https://stackoverflow.com/questions/15262506/sourceurl-equivalent-for-css">//@ sourceURL equivalent for CSS</a></li>
  <li><a href="https://stackoverflow.com/questions/15818636/is-there-something-like-source-maps-for-css">Is there something like source maps for CSS?</a></li>
  </ul>
  <p>MDN in <a href="https://developer.mozilla.org/en-US/docs/Tools/Style_Editor#Source_map_support" rel="nofollow noreferrer">Style Editor</a> states a possibility but it seems to be for <em>Sass</em>.</p>
  <h3>Update on reply</h3>
  <p>Using <code>sourceMappingURL</code> &amp; <code>sourceURL</code> has some incomplete result:</p>
  <ul>
  <li><p><strong>Inspector</strong> still shows file as <code>blob</code> ❎<br />
  <code>blob:moz-extension://*****-****-******/*****-****-******</code></p>
  </li>
  <li><p><strong>Style Editor</strong> lists file name ✅</p>
  </li>
  <li><p><strong>Style Editor</strong> fails to display file (since there is no real URL) ❎</p>
  </li>
  </ul>
  <pre><code>Error while fetching an original source: NetworkError when attempting to fetch resource. 
  Source URL: moz-extension://*****-****-******/****.css
  </code></pre>