Create responsive background images that auto-center

Hello,

I am just learning WP but have been enjoying the Site Origin plugins immensely.

My site is: giantinflatablepolarbear.com, I’m using the MyStile theme, and I’ve got a visual editor row with a background image that covers the full-width screen.

However, when I view it in portrait tablet mode, the image itself does not resize and simply gets cut down. I’ve followed the thread here which seemed to help for a lot, but didn’t fix this.

Could you suggest how to fix this and the best settings for it? Also, should my background be on the visual editor row or the overall row (wrench)?

Lastly, is there any way to resize buttons responsively? These look quite large on mobile/tablets.

Thank you for the help!