Customizing the Navigation Portlet

I'm trying to redo our navigation and it appears that the NS-generated one could be a little more accessible with CSS classes... The only distinction you can make is between open/closed categories for changing the bullets and text size.

I want to use the automated menu, but it would be really nice if you made the classes distinct by which tier or level they are on. This way you can make the subcategories smaller/different than the top-level categories... this is a very logical way to display a menu, so I think it should be an option.

Unless I can change the style of a class based on the rowspan of the <td>, I might be out of luck. I am aware of the hardcoding option, but once you start doing this too much it defeats the purpose of using Netsuite for your webstore.