What problem does it solve? Building a consistent design system for Expo / React Native apps that target both web and native iOS is hard: tokens drift, components leak raw style props, and web builds end up inert without hover, focus, or cursor states. This Skill provides 63 prioritized rules across 11 categories so shared UI stays token-driven, variant-based, and native-feeling on both platforms. ## Core Features & Use Cases - Token Architecture & Theming: Defines a three-layer token scale (raw, semantic, component) inside a single Unistyles theme, with runtime theme switching that avoids full JavaScript re-renders. - Component API Contracts: Enforces the Airbnb DLS pattern of variant and slot props over raw style escape hatches, with compound variants, ref forwarding, and accessibility baked into the contract. - Cross-Platform Parity & Performance: Covers Unistyles _web pseudo-states, Platform splits, FlashList virtualization, Reanimated UI-thread animation, Gesture Handler, and Skia drawing surfaces. - Use Case: When building a clinic app's appointment calendar, treatment-note editor, or body-chart drawing canvas, apply these rules to compose domain components from design system primitives with offline-first autosave and optimistic writes. ## Quick Start Ask the assistant to review or build a shared React Native component, token, or theme using the expo-design-system guidelines for web and iOS parity.
