Why is adaptive not working?

Question

css

Please tell me, there is a site on a test hosting xn--e1aybc.kz/gpx and the adaptive does not work.
Checked by standard means (reducing the browser window and through the http://ami.responsivedesign.is service).

But when the customer began to check, he found that the site is adaptive.
Tell me how to fix it so that I don’t rewrite everything again?

Answer 1

Apparently because the viewport is commented out. Here is this line:

<!--meta(name='viewport', content='width=device-width, initial-scale=0.3')-->