Problems with responsive elements

Hi guys,

I really need some help.

I have a grid row with 3 columns, I have set the first cell to hide on mobile and the third cell also to hide on mobile, which is great on an actual mobile, but doesn’t work on my ipad.

How do I tell the theme that a certain screen width should be treated as “mobile”

And a more complex option, is it possible to have grid row where on desktop 3 cells show, on ipad (portrait and landscape) 2 cells show and on phone only 1 cell?

Thanks