Brand production doctrine
These modules extract transferable production-system lessons from the complete Duolingo Design audit. They do not reproduce Duolingo's identity, assets, voice, geometry, palette, typography, character, or copy.
Use the modules as a connected contract: narrative determines what may be claimed; architecture determines ownership; marks, type, and imagery express the identity; editorial and lexicon rules control language; motion controls character behavior; asset governance controls distribution.
Every project must supply original values and evidence. A reference is a source of system insight, never a style prompt.