[Zope] tags for tree tags?

I noticed that tree attains it's look through the use of tables. I'm attempting to avoid the use of tables except for tabular data, for a number of reasons, not the least of which that I want to appeal to a blind audience. Also, I want to do trees 'backwards': Item1 - Subitem1 + Subitem2 - subSubitem1 + etcetera. What do I need to do to control the formatting of the tables? I'd like to do it purely through css margin-right calls. Thanks, ~mindlace