How to make a blurry block on top of a Yandex map?

Question

css

1. It is Yandex maps.
2. The background of the blurred block moves with the map.

From what I've tried:
- html2canvas: won't screen map tiles
- -moz-element(): works, but only if written in inspector and only in mozilla
upd1: I'm not asking what I should search in google. And I know how this background is made, how filters and canvas work. I ask how to do it in the case I described.
upd2: Actually this is what I want (only works in mozilla) https://jsfiddle.net/2e4v5pLL/2/

Answer 1

Look for js scripts "blurred transparent background", "milky glass effect", etc. Google has a lot of options. But bundled with Yandex maps, it will most likely work very slowly.