It's not really possible to do what you want to do (at least not without generating a CSS rule for every possible percentage value), but you can get damn close

It's not really possible to do what you want to do (at least not without generating a CSS rule for every possible percentage value), but you can get damn close by calculating the right rotation (apparently "percent * 1.8 - 90") and setting the "transform" properties yourself. EDIT: here's a "pure CSS" version: http://codepen.io/tlrobinson/pen/aGvrF http://codepen.io/tlrobinson/pen/aGvrF