Why is the block not lengthening because of the float?

Question

css

There is a block in which the background is replicated.
There are two other blocks in this block with a background, and float:left is written to put them side by side;
And as soon as you register such a property, the background stops repeating and the main block, in which everything is placed, stops stretching in height.
If you remove property float:left; blocks go one after another, i.e. not as it should, but the background block is stretched in height and the background is replicated.
How to deal with such a disadvantage?

Answer 1

overflow: hidden on the parent. Have you been banned on Google?
float parent collapses

Answer 2

don't use float
use flexbox as the default for everything
see my article on flexbox first