How to typeset new elements for adaptive?

Question

Layout

I'll explain now. There is a layout that says 768px wide, but for 320px it looks completely different, that is, there are new elements, new blocks (such as with advertising, for example).
How to layout it as an adaptive block? How to add a new block to the layout specifically for the 320px screen? After all, it will be smaller in width from the main 768px

Answer 1

Typeset, as usual, adjust to all the necessary permissions and show-hide on those "widths" on which it is required.

Answer 2

That's what media queries are for.