How does this work?
No website and no menu: everything here is a card — one thing, readable at a glance, independent enough to stand on its own.
Cards belong to a world and grow in families; stacks give them order. What you are looking at is one of them.
Reading the card
NumberTop right, permanent. A number is never reused and never moves to another card.
TurnClick or swipe. The front shows, the back explains — a card has no other sides.
MenuThe three lines, top left: back, turn, the index of this world, and the printable worksheet.
DNAThe sequence in the footer. It identifies a card, even away from this screen.
Every card stands on its own. Take one to the workbench and the rest can stay where they are.