I know my way round css but I'm having difficulty pin pointing where to change the css for just the Tag Cloud

I can change all widget body content but can't seem to track down '.list li' for example

Here's the page http://www.mobilizingmouse.com/mobilizingmouse/

And here's what I have in mind

http://www.mobilizingmouse.com/fearlesstags.tiff

I realize the size is dependent on number of tags per topic

Thanks in advance!