Best CSS-design interface yet

OK, so now I can talk about TypePad’s awesome template builder feature. It’s not easy to build a good interactive interface for something as nuanced as design, but given the standardization of weblog layouts and some very neatly executed preview routines and what I assume is DOM-driven interactivity, the TypePad beta sports the best CSS interface for design I’ve seen yet.
I’ve been waiting for a while for something that would enable you to choose valid CSS options and get immediate feedback on a dummy example, but the problem with this is that CSS can exist in a vacuum, so you don’t always have an example page on which to try out your CSS formatting and layout choices. Since TypePad basically knows what your blog is going to look like, with some simple boilerplate and an interactive preview widget built into its template builder tool, TP offers the sort of handholding that completely hides the markup. Valid CSS+XHTML web design options with a reasonable range of choices that I can imagine a grandmother (like my mom) using.