Slide position and dimension

Hallo,
I am quite sure this problem is related to the theme and not to Master Slider, but I’d like to have a confirmation, because I want to buy the pro version of Master Slider.

Can you see the slider in my web site http://www.lolligroup.com ?
It is left position and not centered, and if I use full width it is too big, even if the screen is full with image.

Do you think the problem is theme related (Zerif Pro, a common theme for WP, I think).
Thanks !