QA Style Sheet
Fastest way for QA to validate any CSS file
If your testing a website style, it doesn't hurt to put it through a good CSS tester for compatible issues. There's plenty of sites that are available to validate a website CSS. I have found that 'QA Style Sheet' is a good quick check on CSS compatibility.
In my test, the 'QA Style Sheet' check has done a good job finding out of date style. The nice thing about the project is that you can make a Bookmarklet so that anytime you need to check a page style, simply click on the bookmark. This is really handy when testing a page that is deep in the login process.
QA Style Sheet Project Description
The QA style sheet highlights specific HTML problems like use of deprecated elements, inaccessible images, layout tables, empty elements, or styling-related maintenance issues. Theoretically, it is "unobtrusive" in a sense that when everything's fine it won't cause any visible changes.
New Owner Needed
The folks over at QA Style Sheet are looking for a new owner. If you're a CSS expert and have some time to spare, it might be a good way to give back.