This has probably been asked a lot, but i couldn't find an answer.

I have a theme (destyle) with a menu bar, which includes a dropdown menu.
I've changed the menu bars colour and position. you can see it here

www.www.taarttoppings.nl/nieuwesite/concrete5.4.2.2...

In safari, it looks fine, in google chrome theres a slight change, but in firefox its all the way up into my header.
I really want this to work the same in all my browsers.
is there a solution for this?

Thanks!