How to make a scroll of a certain block, but on the whole screen?

Question

Layout

There is a block with the overflow-y: auto style, all page content fits on the screen. The entire scroll takes place in a smaller block, where all the content is. It is necessary that this block scrolls at any point in the document when scrolling.
PS For those who can not understand what I mean. Please don't try to list mouse events.

Answer 1

If someone is interested in how to do such a thing, here is the code that allows you to do this:
https://jsfiddle.net/Zebren/rwbpo3ft/