Keep widgets aligned on mobile devices

Hello,

I’ve noticed an issue where my website’s pages go completely out of line on a mobile display. My images are set to take up the entirety of the widget but, on smaller displays, the widgets will align vertically rather than in rows.

This causes a big issue for me as, a banner could look fine on a mobile screen but then look terrible on a mobile device (See the URL I’ve put in a private comment to see this in action).

Is there any way that I can fix the widgets to **always** display in rows no matter what?

Thanks in advance :)