Invisible is not complex. Invisible is a simple, small and modular CSS framework.
It provides a reset, a resizable (or fluid, whatever you call it) layout system and some other stuff.
Resize this browser window, zoom this page, change the font size. Enjoy Invisible CSS! ;)
$ sudo pip install clevercss cssutils pypake
$ bzr branch lp:invisible
$ cd invisible
$ pypake modules=reset,layout,layout2,fonts step=2