Mobile landscape keyboard hiding input text

Typing on mobile devices in landscape mode makes it impossible to see what you type.
In this example, the input box gets pushed up and the keyboard gets placed below the submit button:

On this screenshot (different device and keyboard), the keyboard covers the input box. The focus in on the topic body but I can only see the title.

Can anything be done about that? My users probably don’t want to switch keyboards or dislike typing in portrait mode.

Why would you be in landscape mode for Discourse? That’s not really supported, because 90% of typical smartphone use is portrait.

There are about 3 users that have complained about not being able to type this way. Since they apparently use other websites in landscape mode without trouble. They thought my suggestion of using portrait is not helpful.
I’m not familiar with mobile browsing, so I wonder if there are keyboards or settings that will allow typing in landscape. Is it possible to hide the address bar of the browser?