What problem does it solve? Building Material Design 3 interfaces requires navigating a large spec covering color roles, typography scales, shape tokens, elevation, motion, 30+ components, and adaptive layouts across multiple platforms. This Skill consolidates that guidance so you can implement or audit MD3 UIs without reading the full specification. ## Core Features & Use Cases - Design token system: Complete reference for md.sys color roles, typescale, shape, elevation, and motion tokens, mapped to Jetpack Compose MaterialTheme, Flutter ThemeData, and web CSS custom properties. - Component catalog: 30+ components (buttons, FABs, text fields, navigation, lists, dialogs) with Compose composables, @material/web elements, and spec-aligned CSS fallbacks for unimplemented elements. - Adaptive layouts: Canonical layouts (feed, list-detail, supporting pane), window size classes, foldable posture handling, and edge-to-edge/insets guidance. - MD3 compliance audit: Invoke with audit to score an app or page across 10 categories (color, typography, shape, accessibility, etc.) and receive a prioritized fix report. - Use Case: Ask for a responsive app shell with navigation rail and top app bar, and receive Compose or web code using correct tokens, tonal pairing, and breakpoint behavior. ## Quick Start Ask the assistant to build a Material Design 3 settings screen in Jetpack Compose with dynamic color and a navigation rail that adapts to window size classes.