framer-motion（Framer Motion 工具）

Framer Motion Skill

When to use

• Adding page transitions or route animations.
• Creating component enter/exit animations.
• Building gesture interactions (drag, hover, tap).
• Animating lists with stagger effects.

Guardrails

• Keep animations under 300ms for snappiness.
• Always respect prefers-reduced-motion.
• Use variants for complex, coordinated animations (not inline).
• Animate transform/opacity only (avoid layout thrash).

Workflow checklist

1. Identify what should animate and when (mount, route change, user interaction).
2. Define variants for multi-state animations (initial, animate, exit).
3. Use motion components (motion.div, motion.span) for animated elements.
4. Coordinate children with staggerChildren in parent variants.
5. Test with reduced motion to ensure accessible fallbacks.

Common patterns

Page transitions

import { motion } from 'framer-motion'

export function PageTransition({ children }: { children: React.ReactNode }) {
  return (
    <motion.div
      initial={{ opacity: 0, y: 20 }}
      animate={{ opacity: 1, y: 0 }}
      exit={{ opacity: 0, y: -20 }}
      transition={{ duration: 0.3 }}
    >
      {children}
    </motion.div>
  )
}

Stagger children

const container = {
  hidden: { opacity: 0 },
  show: {
    opacity: 1,
    transition: {
      staggerChildren: 0.1
    }
  }
}

const item = {
  hidden: { opacity: 0, y: 20 },
  show: { opacity: 1, y: 0 }
}

<motion.div variants={container} initial="hidden" animate="show">
  {items.map(item => (
    <motion.div key={item.id} variants={item}>
      {item.content}
    </motion.div>
  ))}
</motion.div>

Best practices

• ✅ Use variants for readability and reusability
• ✅ Keep duration under 300ms for UI responsiveness
• ✅ Animate transform/opacity (GPU-accelerated)
• ✅ Add layout prop for automatic layout animations
• ❌ Don't animate width/height directly (causes layout thrash)
• ❌ Don't nest many motion components (performance)

References

• Library patterns: docs/dev-1/docs/16-library-patterns.md#framer-motion
• Design system: docs/dev-1/docs/13-unified-design-system.md (animation tokens)

Tooling

• Use Context7 or web search for framer-motion API details when needed.