Styling the first hierarchy level links

Hi,

I wonder whether anyone can think of how I could apply a CSS style to the links in the first hierarchy in the sidebar.

Sidebar looks as follows:

-topic1
–topic1.1
–topic1.2
—topic1.2.1
–topic1.3
-topic2
–topic2.1
—topic2.1.1
–topic2.2
–topic2.3

I now would like the “toplevel” links (topic1, topic2) to be displayed in bold, whereas the rest can stay unbolded. It works if I use (strong) tags in the title itself, but that seems to me to be sort of a dirty hack.

I don’t know however how I could apply a specific tag only to a specific hierarchical element in a list.

Talk about brains and wrapping 😉