Laws of UX.

Universal cognitive, perceptual, and behavioral heuristics that decide what a UI composes — how many pricing tiers fit on a screen, where a primary action anchors in scanning order, when a progress indicator earns its place, why a settings list needs grouping. The active DESIGN.md decides brand visual language; the existing craft files decide rendering rules (color, typography, motion, states, ARIA, RTL, forms); this file decides composition rules grounded in named research.