Customize mobile navigation Vantage Theme

Hello everyone,
first of all I have to say, I really like the vantage theme, after bit of try and error I could easily figure out how to customize tags etc. so thanks for the great theme… it looks really good.

I do have a question about the mobile navigation though.

In the latest Version of the theme the mobile navigation will slide in from the left side after you clicked on the item for the menu. I figured out how to customize colors etc. this is pretty easy no coding for general customization required but is it possible to customize the animation of the menu, so that the menu after you clicked it will slide from above to its final position instead of from the left to the right… which file do I have to edit to make this possible…

I hope I could describe my plan quite well… and someone here could help me out.

Thanks in advance

cheers
Kai