gameboy ui to simulate keypresses for touch

[SheepTester]

de tw@JARS_ARG dms

The buttons can arrange themselves like so in landscape mode and like the following in portrait mode I'm not sure what the best way to calculate the ideal layout is, taking into account custom stage sizes. Perhaps at a minimum it just needs to look tolerable for the default 480 by 360 size, or the CSS can be pre-generated using JS.