Problem with box for drop down menu disappearing

Hello,

I have an Ecwid store using the Highend Theme. My issue is the store uses drop down boxes to choose item options. It looks fine on their end but the box disappears on my site. I tried to see if I could insert some CSS to fix this, but have not been able to get the desired results. I am no expert by any means.

I have attached a screenshot to show what I am referring to. Any help would be appreciated.

http://www.teamconcours.com/store

Regards,
Greg