possible spoiler or bug idk: if you rotate the document with the chrome pdf viewer the vertical 4 arrow in the first page starts to light up green intermittently and constantly make sounds, it doesn't seem to be a intended mechanich but maybe it is and if thats the case wow I'm lost. I didn't accept cookies idk if it is relevant
edit: something similar happens with horizontal scroll, and it makes two square make sounds at the same time and it becomes very annoying which is the main reason for why I dont think it is intended