This is not a 'CSS Framework' or anything of that order; it is simply a collection of reusable CSS components. I try to keep the CSS as up-to-date as possible, meaning that I will choose i.e. 'advanced' CSS3 selectors and properties where appropriate but will also use hacks and workarounds.
The CSS is heavily documented and not meant to be copied as-is. Feel free to use what seems useful but please clean up the CSS. Use Internet Explorer hacks in conditional comments if it seems appropriate. I've chosen to have all CSS in one file for easier maintenance, because it saves a HTTP request and because the context of a certain rule is more clear. If you already use Conditional Comments in your project, please add the rules to those files.
I'm pretty sure there's heaps of room for improvement: feedback is more than welcome!