br = Ferrum::Browser.new   # no matter :headless true or false
br.evaluate "[innerHeight, outerHeight]"

The innerHeight is expected to be smaller than outerHeight: https://developer.mozilla.org/en-US/docs/Web/API/Window/innerHeight
But in fact they are equal and innerHeight is frozen (at 768). When I resize the window it does not change.
Also because of this the third-party JS scripts are unable to correctly obtain the client area and resize the content beyond it.

v 0.11, macOS Big Sur