Speed is not a duration, it is a feeling. An interface that animates for 600 ms can feel faster than one that snaps in 100 ms, if the motion is shaped right.
Speed is perceived
Fast starts and soft landings read as quick and confident. Linear motion reads as mechanical, and slow starts read as lag, even when the total time is short.
Our defaults
A dawn curve, fast out and slow in, for everything that enters
An orbit curve for anything that moves between states
Lines staggered by 90 ms, cards by 120 ms
Write these down like you write down colours, and every page of the site will move with the same rhythm.
