Now shared stylesheets are provided by
upload.wikimedia.org
https://wikitech.leuksman.com/index.php?title=Server_admin_log&diff=174…
This breaks javascript code adding custom rules.
Just a checking like if (document.styleSheets[0].cssRules) now throws
"0x805303e8 (NS_ERROR_DOM_SECURITY_ERR)"
http://mrclay.org/index.php/2008/09/06/case-of-the-ns_error_dom_security_er…
Is there a recommended way to do this?