Completely optional and can be personal preference but we might have over-commented some of the lines, some comments are genuinely useful and are great to document code but others might be consider self explanatory.

I think you're right about style- I have put most of the comments in as a reminder to myself when I look at it again- not very neat and collaborative, but useful for me while I'm learning and possibly reusing in future modules. If there's a better or more standard way of doing that, I'm happy to comply? Thanks

This is an awesome touch, minor point is that when the background becomes red, then a new timer could reset it back to the original background (until it's done counting and it goes back to red). How can we implement that?

Reset screen to white when timer set.

Completely optional, can we add some guards against edge cases such as empty input, negative values, and (potentially) 0? Everything would trigger an alarm right away with the current implementation.

Updated edge cases of 0 and -1 to not accept inputs.