The elevator, up and down
The elevator accepts Applicants holding 50 certificates from the floor before, above or below as applicable. Capacity: one (1) Applicant.
The building has floors above the Lobby and a basement below it. The elevator is how you get between them. Open the Elevator tab to stand in the car.
A floor opens once you hold 50 certificates from the floor before it, going up or going down, and it stays open. The Lobby leads both ways: up to Floor 2 and down to Floor B1. From there, each floor opens the next one along. Your File says how many you still need.
On the panel, a lit button is a floor you can ride to. Press it and the car takes you there, and the doors open on that floor's first room. Press a dark button and the display says why it is dark. Most will stay dark for a long time.
The numbers do not go in a straight line. There is no Floor 4 and no Floor 13, and there is at least one floor with a fraction.
Every floor has one rule that holds in all of its rooms. You learn it by arriving. It is then shown on Your File.
Your pockets ride with you. Floors you have opened stay open, so you can go back at any time to finish one.