What problem does it solve? Animation code often ships with subtle craft defects — sluggish easing, wrong transform origins, non-GPU properties, missing reduced-motion handling — that make interfaces feel slow or broken even when they technically work. This Skill reviews motion code against a strict, opinionated standards catalog so these issues are caught before merge. ## Core Features & Use Cases - Standards-based review: Evaluates every animation in a diff against ten non-negotiable rules covering easing curves, sub-300ms durations, transform origins, interruptibility, GPU-only properties, and accessibility. - Structured findings output: Produces a Before/After/Why findings table plus a tiered verdict (feel-breaking regressions, performance, timing, accessibility) ending in an explicit Block or Approve decision. - Precise citations: Pulls exact cubic-bezier curves, duration tables, and spring configs from STANDARDS.md instead of approximating values. - Use Case: A developer opens a pull request adding a dropdown that animates with transition: all 400ms ease-in from scale(0). The review flags the unbounded transition, the ease-in curve, the over-budget duration, and the from-nothing scale, then prescribes transform 200ms with a strong ease-out from scale(0.95) plus opacity. ## Quick Start Review the animation and motion code in this pull request diff and give me a findings table with a block or approve verdict.
