How to create responsive pages, layouts in

Thank you all for your contribution, I’m using the new responsive engine and after following and adapting the videos to the new engine i got the responsiveness but I have the problem where I’d like to have bigger pictures in desktop mode, like the ones on the bottom in this screenshot, but I get the upper ones if I make the columns responsive:

While The upper ones are good on mobile as I want 2 columns with pictures of 150 px max but they stay small on desktop while the bottom ones aren’t responsive and stay 4 columns instead of 2:

The main problem is that I can’t have fixed columns AND minimum column width togheter but it has to be variable columns, so they get the minimum width of the image inside.

I tried many things, the only thing that I have to try is changing the column/row/fixed container layout.

I’m using column for index and all the children are like the parent as I suppose that it’s the best option also since I’m aiming mostly at smartphones