How do the guided tours work?

Open the Guide (the "Guide" button at the bottom left, from version 1.9.17) and click a tour. The screen dims, one button or card at a time is lit up, and a small card next to it explains what it does and when you need it, sometimes with a tip. Press "Next" and "Back", or use the right and left arrow keys. Press Escape or the X on the card to close the tour at any moment; you can start it again whenever you like. The tours drive the app for you: the New Book tour walks through all four steps of the form, the Settings tours switch between engines and sections, and the Codex tour opens the Codex and goes from section to section. When a tour ends, the app goes back to how you left it. While a tour runs, the page under it is not clickable: that is on purpose, so nothing is changed by accident.