Why is responsiveness not working?

Question

css

The Google service writes that the site is adaptive, the HTTP://ami.responsivedesign.is service also displays as it should, emulators in the browser display correctly. But on real devices, the site is awry. What is it connected with?
HTTP://artprimprom.rf/

Answer 1

Show me the site.
But the viewport is probably set incorrectly.

Answer 2

Well, of course there will be a difference. Browsers on tablet and mobile have many properties that are displayed "in their own way")). The layout designer must have a phone and tablet available))

Answer 3

And not so good on desktop either.