There is no Firefox specific way to write font-family: inherit;
. Mozilla support inherit like any other browser, if that is what you mean?
Vendor-prefixed properties (like those used for some CSS3 properties) are only used for properties that are still "experimental" or evolving. The inherit
keyword has been around for ages and therefor Firefox, like any other browser, implement it the way the CSS-specification states, without a vendor prefix.
If you want to target only Firefox with some specific CSS, this SO answer states that you can wrap the Mozilla specific properties with a @-moz-document
rule. As only Mozilla will recognize that as valid CSS, all other browsers will ignore it. A bit "hacky" perhaps, but it sounds like your best shot.
Edit:
To target only IE with specific CSS, one way is to put it in an IE-specific stylesheet file, and then use the conditional comments for IE. All browsers but IE will see this as an HTML-comment, and therefor ignore it, but IE will apply the styling in that file.
<!--[if IE]>
<link rel="stylesheet" href="ie.css" type="text/css" />
<![endif]-->