Menu child issue eco nature theme

I bought the eco nature pro theme, but it is technical a little difficult so I’m still using the free eco nature theme because that one is working for my site. I want to make use of the support option from my pro theme because I have an issue with the menu child items. Those items stay behind the Title and the crumb box on the page below the menu. How and where can I fix this? In the style.css? Thank you in advance.