How to style WordPress/FeedBurner feeds?

Question

css

WordPress RSS feeds, even those created through FeedBurner, arrive in the mail in an ugly form - without image alignment and wrapping styles. The classes are all reset and it is not clear how you can set them up, except for the hard way in the posts themselves to prescribe something like:
style="float:left; margin: 5px...
But this, as we know, does not suit us :)
Maybe there is some kind of hack for WordPress itself or a setting in the feedburner for mailing lists that I can't find?
Thank you.