gk4 used as header

Hi, I'm using a GK4 module as a header, because the client wants image rotator at header position.
I have programmed it with no problems and used gk_university module style.
It works just fine on the desktop view, the problem is with header module responsiveness on mobile and tablet - images (slides) are resized proportionally, no problem there, but the background of the header module is not resizing accordingly. I cannot change it with CSS override (probably don't know how) as the size of the module background is generated by inline style, which I believe is generated by javascript (if I understand it correctly)?
I am using ''frontpage fullscreen'' suffix with template styling, and since GK4 with gk_university style was not intended for use on Quark theme, there are some issues.
Can you suggest any solution?
Thank you

Hi,
Could you please provide me with a URL to your website, either here or via PM (click the “Private Message” text underneath my avatar) so that I may analyze it?