I'm struggling to minimize the frame width and height for the product base image gallery (Fotorama).

I have inspected the browser code and noticed that if I change the following width and height the related Fotorama Frame size change however, did not found the actual location to customized the white border size (width and height):

Basically when I change the above width: 707px; height: 707px; through browser inspect I can see the changes but no where found the actual file or location to change the value.

I will appreciate if anyone can help me.

Thank you.