VK browser messes with position:fixed, how to fix it?

Question

css

When opening the site in the browser of the VKontakte application, the fixed menu looks disgusting.
What happens: when scrolling, VK smoothly hides the page title, increasing the screen viewport by 40-50px, the menu (and other elements) with position: fixed are shifted to this gap and remain in this position, which is completely unacceptable. What it looks like:

How to solve the problem? I see two ways:
1. Determine that this is a VKontakte browser and set position:absolute for the menu so that it scrolls along with the content.
2. Determine that this is a VK browser and recalculate the height of the block at ScrollStart.
In any case, first of all, you need to determine that this is the VK browser, how to do this? Maybe there is already a solution?

Answer 1

why bike? write to the developer of the VK browser and that's it.

Answer 2

Try by User-Agent header (in JS - navigator.userAgent variable)

Answer 3

There is a button at the top right, select the "open in safari" link in it ))
But seriously, in IOS all browsers use the same webkit, this is the company's policy. There is most likely a problem with the site itself.