Periodic table scrolling

[CasperWA]

From #276:

One can somehow end up in a state, where the periodic table gets broader than the app width (and there was a horizontal scroll bar).
I'm not able to reproduce this myself, so I'm just mentioning this in case it pops up again.

This is kept as a "reminder" issue to log if this happens for others, i.e., if this has happened to you, please write a comment in this issue or do a "thumbs up".