Venture theme: Banner isn´t responsive

[interfashinc]

Hi!

I´m using Venture Theme. I setted a banner (1120*373px) on the top of my page. When I try responsive view, it gets cropped.

Before this theme, I was using Minimal Theme, and I read it was something in the theme.scss code. I modified it and it went perfect; but I can't find in any forum the respective code to fix the Venture Theme in that way.

Thank you.

Desktop preview.

Responsive preview.