The faces, sizes, and weights in one place — how a Lumos surface reads from top to bottom.
Headlines and the single italic accent word. Never body or UI.
Body, leads, labels, captions, UI. Emphasis from weight (SemiBold / Bold).
Numbers, tokens, code, timestamps — never prose.
Tight for display (~1.0), open for body (1.5–1.6).
Two families carry the system. Adding a face dilutes the voice.