080104-motion-animation
Installation
SKILL.md
Motion & Animation Principles
Animation and motion design for frontend interfaces — timing, easing, physics, micro-interactions, and performance. Covers both brand (expressive) and product (task-serving) motion.
References
| Topic | File |
|---|---|
| Timing values, easing curves, CSS/JS implementations, platform standards | references/timing-easing.md |
| Spring physics, spatial continuity, shared transitions, reduced motion, interruption handling | references/motion-principles.md |
| Press feedback, ripple, skeleton, toast, toggle, dropdown, focus, tabs, progress | references/micro-interactions.md |
Core Rules
- Timing: Micro-interactions 150-300ms. Complex transitions ≤400ms. Exit 60-70% of enter. Stagger 30-50ms per item.
- Easing: Ease-out for entering (exponential: quart/quint/expo), ease-in for exiting. No bounce, no elastic, no linear for UI.
- Performance: Animate transform/opacity only. Never width/height/top/left. Interruptible animations. 60fps (~16ms/frame).
- Reduced motion: Respect
prefers-reduced-motion. Data readable immediately. No orchestrated page-load sequences. - Product vs Brand: Product = 150-250ms, conveys state only. Brand = more expressive, spring physics, stagger, shared elements.