Collection page banner formatting issue for mobile

Hello

My collection page banners look good for desktop/tablet view but for mobile they look quite compact, with all the banner images on the same line which makes it hard to view on mobile, and I would like the banner images to stretch the width of the screen with the text underneath it.

I have attached a current view of how it looks for mobile and a quick basic mock up of how I would like to look on mobile.

Live URL of example collection page is: https://display-sign.co.uk/collections/chalkboards

Any help would be greatly appreciated!