I can't make completely responsive columns in new responsive engine

Continuing the discussion from How to create responsive pages, layouts in bubble.io:

I have the problem where columns stay too close to the minimum comun width, so if 150 px is fine on mobile, it’s too small on desktop but I can’t conditionally change that value and have to make 2 different versions of the repeaatable group.

Am i doing something wrong?

Bubble’s built-in RG behavior works well in most cases, but if you’d like more explicit control over the number of RG columns at different page widths, this tip might be helpful (if you’re not averse to getting your hands dirty with a bit of CSS).

Thank you, I tried but I’m new to bubble, how do I implement CSS?