Thanks Karen!
I took a look and would recommend adding CSS like this to the bottom of your theme’s style.css file:
#tribe-events-content .type-tribe_events {
border-bottom: 1px solid #999;
padding-bottom: 1em;
padding-top: 1em;
}
You will have to play around with the styles, change the colors to your needs and such, but I hope this is a helpful starting place. Here’s how that CSS makes things look on your site:

I will not be able to help with any further customization-related questions,
but I hope this helps! If you want to make further tweaks on your pages, definitely check out a [free!] tool like Firebug if you use FireFox, or the Developer Tools for either Safari or Chrome. They have “Inspector” tools that let you zoom right over the element whose styles you’d like to change, so you can see what CSS is required to make the changes you want to make.
Cheers,
George