This is meant as a light hearted question: how could you have gotten this far making a viewport tester and the mobile website development journey without understanding and dealing with the most important and disruptive behavior in mobile viewports? Like I get that this is just a free project and it does what it does.

* with and without the keyboard focused,

* in each of the preference states (e.g. tab bar vs single tab for iOS, which influences whether there’s a compact address/button bar on the bottom or an address bar at top plus a button bar at bottom), and

* both of those in portrait and landscape