Chapter 05
It opens
One gesture runs through the whole brand: a page turning. Motion is short, eased, and always reversible. If a movement can’t be explained as “a page opened” or “a thing arrived”, cut it.
Fig. 3 — the two curves
How things ease
Signature is symmetrical — a page opens the way it closes. Arrival overshoots slightly and settles, for things entering the screen.
Timing
900ms for the fan, staggered 0/80/160ms from the centre page outward. 150ms for everything UI. Click a row to copy it.
Reduced motion is not a downgrade.
Under prefers-reduced-motion the fan holds open, and the reader falls back to vertical scroll instead of page-flip. Every state must be legible with all motion removed — the animation is a flourish on top of a complete design, never the thing that communicates.