Not only can you post a link to the page in question, we prefer it. Post it as yoursiteDOTcom if you don't want the bots to pick it up yet.
In this case, you can add to the bottom of your stylesheet:
.categoryListBoxContents {font-size: 1.3em;}
Adjust the 1.3 to taste.
For future reference, install the Firefox browser and the Web Developer plugin for Firefox. You can use those to see where in the stylesheet you change the styling of the various page elements.
Ctrl-Shift-Y will allow you to hover over a section of the page and see the class and id names for that section in the box at the top. The statements in the stylesheet that begin with # are id's and the ones that begin with dots are classes.
Ctrl-Shift-E will open the CSS editor and allow you to edit the stylesheet and see the changes in real time without changing anything permanently. An essential tool.
Some prefer Firebug, which does much the same thing.
(If you're using Firefox 4-6, you'll need to remap the editor shortcut, since Firefox has appropriated Ctrl-Shift-E for an internal function - I use Ctrl-Shift-Q.)