TOC formatting

Hi,

is there a way to modify the toc templates to e.g. making every major
one heading bold and have a padding or margin like this

1. This is a major one heading (BOLD font-weight)
1.1 ... (NORMAL font-weight)
1.2 ... (NORMAL font-weight)
Padding / Margin / Spacing
2. This is a major two heading (BOLD font-weight)
2.1 ... (NORMAL font-weight)
...

I already searched the documentation and the xsl source, but haven't
found a real entry point in the toc.xsl.

Any ideads or suggestions?

Cheers,
Tobias