Background Image Not Being Resized on Low Resolution Devices

[spreadred]

When viewing the webpage on a smaller screen device like a phone, the background image does not scale to a size which would allow visitors to see the entire image. Is this working as designed? My background image is 1200px wide just as yours in the repo.

Could there be some sort of workaround for this? Having visitors being greeted with just a large portion of my head and none of my partner visible is a bit disappointing.