What problem does it solve? Choosing and implementing the right animation technique for the web is hard: developers often reach for heavy libraries when native CSS would suffice, or misuse React animation patterns that break exits, layouts, and performance. This Skill provides a decision ladder and concrete implementation patterns for motion that fits the platform. ## Core Features & Use Cases - Tool selection ladder: Maps each need (hover, keyframes, enter/exit, layout shifts, gestures, scroll-linked effects, page transitions) to the cheapest tool that solves it, from CSS transitions up to GSAP. - Modern CSS patterns: Covers @starting-style, transition-behavior: allow-discrete, scroll-driven animations with view() and scroll() timelines, and the View Transitions API with fallbacks. - Motion/Framer Motion recipes: AnimatePresence enter/exit, layout and layoutId FLIP animations, springs for gestures, whileInView reveals, and useReducedMotion for accessibility. - Use Case: A React developer needs a modal that animates in and out cleanly, cards that reveal on scroll without JavaScript, and a shared-element transition between list and detail views — this Skill provides the exact code patterns and pitfalls for each. ## Quick Start Ask the agent to implement enter and exit animations for a React modal using Motion, with a scroll-driven reveal for the page cards in pure CSS.