How to correctly calculate the height with open tabs on iphone7 in safari?

Question

safari

Hi all. The problem is that on iphone7 in a safari browser you can open tabs in one window and when they open, the browser does not take into account their height and the application hides a little off the screen down. Here you can see on the screenshots:
(without tabs)

(with tabs)
The game is written on canvas and its width and height are set depending on the screen size.
I tried to set the height to 100%, I tried to calculate js-ohm (innerHeight), but it does not help. There is an option to calculate that the iphone device and use calc in css to remove the size of the tabs in advance, but this is not a beautiful solution. Can anyone come across and tell me the best solution or how can I check if the tabs are open?