How to make adaptive blocks?

Question

Adaptive design

There are 2 blocks or columns: 1st image, 2nd text part.
How to make them adaptive for different screen resolutions. For desktop, 2 blocks were in the same row 50 by 50, and for mobile devices, block 2 is transferred to a row and stretched by 100% like the 1st one.

Answer 1

https://developer.mozilla.org/en/docs/Web/CSS/Medi...