How to get this gradient effect on dropdown menu?

I need to recreate the gradient border effect as seen in this image:

The maximenu install I need to put it in is found here:

www.teachertravelguide.com/newtv

How can I get that border effect? Is it done in CSS or am I going to have to create images of some kind?

Hi
you can do something similar, using a shadow with the option "IN"
you can find this option in the maximenu params interface for the styles customization
CEd