@-moz-document

The CSS   rule is a Gecko-specific @-rule that restricts the style rules contained within it based on the URL of the document. It is designed primarily for user style sheets. This @-rule was available since Firefox 1.5.

CSS example:

@-moz-document url("http://www.w3.org/"), url-prefix("http://www.w3.org/Style/"), domain("mozilla.org") { /* CSS rules here apply to: + The page "http://www.w3.org/". + Any page whose URL begins with "http://www.w3.org/Style/" + Any page whose URL's host is "mozilla.org" or ends with ".mozilla.org" */

/* make the above-mentioned pages really ugly */ body { color: purple; background-color: yellow; } }