I am working on my templates/css, and have conquered most of the problems.  However, there is one thing left to do that baffles me:

I list the categories in a sidebar, so users can filter the entries in my blog by category.  At first I displayed this as an indented list, but I didn’t like the amount of space the indents took up.  So I changed to a linear list, but now it’s harder to distinguish between main- and subcategories.

So, ideally, I would like to be able to:
- use an indented list, and control the width of the indent, or
- use a linear list, and be able to display main categories in bold or some way to make them stand out

Can this be done?

Thanks.