Very interesting! Was a real brain twister, had me scrambling for a note pad for the last one lol. Great Work! The screen does go blank when you click into fullscreen until you click again, just fyi. (I am using a very modded version of firefox though keep in mind)
Thanks for the comment :)
I also had to take notes for the last one :D
I tried on chrome, edge, opera, and firefox and it works ok for me. Maybe it's a problem with some extension.
What is your monitor resolution?