Searching for an online CSS editor

I was quite surprised I didn't find any good online css editors.
I have a simple textarea of css selectors and attributes, and I wish to offer some kind of help to the user in editing those rules. The best tool I found is called Sky CSS Tool, and it does a lot of fancy things I like, however it doesn't support attribute generation from the CSS Code itself. Also the project is pretty much left alone for a number of years. After some modernization, this could be a great tool though.