Dropdown in TopMenu

Hi guys, can anyone help of which files do i have to customize so that the drop down works also in the “topmenu”. I have a lot of categoryies, and the “main menu” is already full. I need to add a “topmenu” and divaricate it too.

I would be pleased, if someone can at least tell me if i should look only in the theme files (which i already tried such as base.css or style.css), or it is needed to customize a file that is in wordpress instalation.

The webside uses “intuition” theme, and the address is https://technospol.esy.es/

Sorry for my english, and not wery good technical explanations of the problem… ??