How to reference a 'multi-tag' selector?

Hello,
I am attempting to style a menu and am running into a bit of a problem with the selectors used to identify the element.

For example, the template lists out a class statement, and it reads as follows:

<li class="level1 item1 first">

My issue is, how is this styled using one of the stylesheets?

There is a <DIV> that encloses the <LI> tag that has an ‘id’ reference, but I don’t know the selector to reference the <LI> tag.

Thoughts?