Motion
Motion in Ardent Word exists to explain where something came from and where it went. Nothing moves to be impressive, nothing bounces, and nothing draws attention to itself while somebody is reading.
Each role pairs one duration with one easing curve. Both come from the token file.
Rule
When a reader has asked their system for reduced motion, every transition on this site collapses to effectively nothing. That is a global rule in the base layer, not something each component has to remember.
Streaming text is never animated character by character like a typewriter. An answer arrives in whole words at a readable pace, because a person reading about something that frightens them should not have to wait for a letter at a time.