CSS Help with Top-Navigation Bar

I need some assistance fixing the look of my top-bar of the website.

http://cityofhanahan.com

You can see the top-bar is a blue background. That appears to be fine, but when you rollover the links in the bar, they disappear. I have used the theme settings for the top-bar color and changed it, but yet I don't see any changes.

Any help would be much appreciated!