Browser-Specific Classes

gistfile1.js

// add OS-specific classes for targeting a whole set of browser on one OS.
$('html').addClass('browser-os-'+ (
	navigator.userAgent.match(/Macintosh/) ? 'macos' :
	navigator.userAgent.match(/Windows/) ? 'windows' :
	navigator.userAgent.match(/Linux/) ? 'linux' :
	'unknown')
)
// now add more general browser classes for targeting all version of any one browser. IE disabled since conditional comments added.
.addClass('browser-'+ (
	$.browser.msie    ? 'ie' :
	$.browser.mozilla ? 'ff' : 
	$.browser.webkit  ? 'wk' : 
	$.browser.opera   ? 'op' : 
	'unknown')
)
// make the classes more concise than the tokens jQuery returns, also add version
.addClass('browser-'+ (
	$.browser.msie    ? 'ie-' + navigator.userAgent.match(/MSIE ([\d]+)/     )[1] :
	$.browser.mozilla ? 'ff-' + navigator.userAgent.match(/Firefox\/(\d\.\d?)/)[1] :
	$.browser.webkit  ? 'wk-' + navigator.userAgent.match(/WebKit\/(\d+)/)[1] :
	$.browser.opera   ? 'op-' + navigator.userAgent.match(/Version\/([\d.]+)/)[1] :
	'unknown').replace('.', '-')
);

Use Modernizr when you can. This is for purely visual inconsistencies.