ECC/skills/motion-patterns/SKILL.md

name, description, tags, category, author, metadata

name	description	tags	category	author	metadata
motion-patterns	Production-ready animation patterns for React / Next.js — button, modal, toast, stagger, page transitions, exit animations, scroll, and layout — built on motion-foundations tokens and springs. Use when animating a specific UI element in React or Next.js — button, modal, toast, stagger, page transition, or scroll.	motion animation ui-patterns	frontend	jeff	version 1.0.0

Motion Patterns

Copy-paste patterns for the most common UI animation needs. Every pattern here is built on motion-foundations tokens and springs. Do not define new duration or easing values here — import them.

When to Activate

• Animating a button, card, modal, or toast notification
• Building list entrances with stagger
• Setting up page transitions in Next.js App Router
• Adding entrance or exit animations to conditional content
• Implementing scroll-reveal, scroll-linked progress, or sticky story sections
• Building expanding cards, accordions, or shared-element transitions

Outputs

This skill produces:

• Accessible, SSR-safe animation for all standard UI components
• AnimatePresence-wrapped conditional renders with correct exit behavior
• Page transition wrapper component for Next.js App Router
• Scroll-reveal and scroll-linked patterns using useScroll + useTransform
• Layout animation patterns (layout, layoutId) for expanding and crossfading elements

Principles

• Every pattern imports from motion-foundations. No raw numbers.
• Every conditional render is wrapped in AnimatePresence with a key.
• Exit animations are always defined alongside enter animations — never as an afterthought.
• layout is used only for small, isolated shifts. Large subtrees get explicit transforms.

Rules

1. Always wrap conditional renders in AnimatePresence with a key on the direct child. Without a key, exit animations never fire.
2. Always define exit when defining initial + animate. An animation without an exit is incomplete.
3. Use mode="wait" on page transitions. Enter must not start until exit completes.
4. Never use layout on subtrees with more than ~5 children or deeply nested DOM. Use explicit x/y transforms instead.
5. Stagger interval must stay between 0.05s and 0.10s. Below feels mechanical; above feels sluggish.
6. Modals must always include: focus trap, Escape-key close, scroll lock, role="dialog", aria-modal="true".
7. Scroll reveals use viewport={{ once: true }}. Repeating on scroll-out is distracting, not informative.
8. All token values are imported from motion-foundations. No inline numbers.

Decision Guidance

Choosing the right pattern

Situation	Pattern
Element appears / disappears	AnimatePresence
List of items loading in sequence	Stagger variants
Navigating between routes	Page transition wrapper
Element changes size in place	layout prop
Same element moves across page contexts	layoutId
Element enters when scrolled into view	whileInView
Value tied to scroll position	useScroll + useTransform

When to use mode="wait" vs mode="sync"

Mode	Use when
wait	Page transitions, content swaps (one at a time)
sync	Stacked notifications, list items (overlap is fine)
popLayout	Items removed from a reflow list

Core Concepts

AnimatePresence contract

Three things must always be true:

1. AnimatePresence wraps the conditional
2. The direct child has a key
3. The child has an exit prop

Miss any one of these and the exit animation silently fails.

layout vs layoutId

• layout — animates the element's own size/position change in place
• layoutId — links two separate elements, crossfading between them across renders

Use layout="position" on text inside an expanding container to prevent text reflow from animating.

Code Examples

Button feedback

"use client"
import { motion } from "motion/react"
import { springs, motionTokens } from "@/lib/motion-tokens"

<motion.button
  whileHover={{ scale: motionTokens.scale.pop }}
  whileTap={{ scale: motionTokens.scale.press }}
  transition={springs.snappy}
/>

Stagger list

"use client"
import { motion } from "motion/react"
import { motionTokens, springs } from "@/lib/motion-tokens"

const container = {
  hidden: {},
  visible: {
    transition: {
      staggerChildren: 0.08,   // within the 0.05–0.10 rule
      delayChildren: 0.1,
    },
  },
}

const item = {
  hidden:  { opacity: 0, y: motionTokens.distance.md },
  visible: { opacity: 1, y: 0, transition: springs.gentle },
}

<motion.ul variants={container} initial="hidden" animate="visible">
  {items.map((i) => (
    <motion.li key={i.id} variants={item} />
  ))}
</motion.ul>

Modal

"use client"
import { motion, AnimatePresence } from "motion/react"
import { motionTokens, springs } from "@/lib/motion-tokens"

// Wrap at the call site:
// <AnimatePresence>{isOpen && <Modal key="modal" />}</AnimatePresence>

export function Modal({ onClose }: { onClose: () => void }) {
  return (
    <>
      {/* Overlay */}
      <motion.div
        className="fixed inset-0 bg-black/50"
        initial={{ opacity: 0 }}
        animate={{ opacity: 1 }}
        exit={{ opacity: 0 }}
        onClick={onClose}
      />

      {/* Panel — accessibility requirements: focus trap, Escape close,
          scroll lock, role="dialog", aria-modal="true" */}
      <motion.div
        role="dialog"
        aria-modal="true"
        className="fixed inset-x-4 top-1/2 -translate-y-1/2 rounded-xl bg-white p-6"
        initial={{
          opacity: 0,
          scale: motionTokens.scale.press,
          y: motionTokens.distance.sm,
        }}
        animate={{ opacity: 1, scale: 1, y: 0 }}
        exit={{
          opacity: 0,
          scale: motionTokens.scale.press,
          y: motionTokens.distance.sm,
        }}
        transition={springs.gentle}
      />
    </>
  )
}

Toast stack

"use client"
import { motion, AnimatePresence } from "motion/react"
import { motionTokens, springs } from "@/lib/motion-tokens"

<AnimatePresence mode="sync">
  {toasts.map((t) => (
    <motion.div
      key={t.id}
      layout
      initial={{
        opacity: 0,
        x: motionTokens.distance.xl,
        scale: motionTokens.scale.subtle,
      }}
      animate={{ opacity: 1, x: 0, scale: 1 }}
      exit={{
        opacity: 0,
        x: motionTokens.distance.xl,
        scale: motionTokens.scale.subtle,
      }}
      transition={springs.snappy}
    />
  ))}
</AnimatePresence>

Page transition (Next.js App Router)

// components/page-transition.tsx
"use client"
import { motion, AnimatePresence } from "motion/react"
import { usePathname } from "next/navigation"
import { motionTokens } from "@/lib/motion-tokens"

const variants = {
  initial: { opacity: 0, y: motionTokens.distance.sm },
  enter:   { opacity: 1, y: 0 },
  exit:    { opacity: 0, y: -motionTokens.distance.sm },
}

export function PageTransition({ children }: { children: React.ReactNode }) {
  const pathname = usePathname()
  return (
    <AnimatePresence mode="wait">
      <motion.div
        key={pathname}
        variants={variants}
        initial="initial"
        animate="enter"
        exit="exit"
        transition={{
          duration: motionTokens.duration.normal,
          ease: motionTokens.easing.smooth,
        }}
      >
        {children}
      </motion.div>
    </AnimatePresence>
  )
}

Scroll reveal

"use client"
import { motion } from "motion/react"
import { motionTokens, springs } from "@/lib/motion-tokens"

<motion.div
  initial={{ opacity: 0, y: motionTokens.distance.lg }}
  whileInView={{ opacity: 1, y: 0 }}
  viewport={{ once: true, margin: "-80px" }}   // once: true — rule 7
  transition={{ duration: motionTokens.duration.slow, ease: motionTokens.easing.smooth }}
/>

Scroll progress bar

"use client"
import { motion, useScroll } from "motion/react"

export function ScrollProgress() {
  const { scrollYProgress } = useScroll()
  return (
    <motion.div
      className="fixed top-0 left-0 h-1 bg-indigo-500 origin-left w-full"
      style={{ scaleX: scrollYProgress }}
    />
  )
}

Expanding card

"use client"
import { useState } from "react"
import { motion, AnimatePresence } from "motion/react"
import { springs, motionTokens } from "@/lib/motion-tokens"

export function ExpandingCard({ title, body }: { title: string; body: string }) {
  const [expanded, setExpanded] = useState(false)

  return (
    <motion.div layout onClick={() => setExpanded(!expanded)} className="cursor-pointer">
      {/* layout="position" prevents text reflow from animating */}
      <motion.h2 layout="position" className="font-semibold">
        {title}
      </motion.h2>

      <AnimatePresence>
        {expanded && (
          <motion.p
            key="body"
            initial={{ opacity: 0 }}
            animate={{ opacity: 1 }}
            exit={{ opacity: 0 }}
            transition={{ duration: motionTokens.duration.fast }}
          >
            {body}
          </motion.p>
        )}
      </AnimatePresence>
    </motion.div>
  )
}

Shared-element crossfade

// Source context
<motion.img layoutId="hero-image" src={src} className="w-16 h-16 rounded" />

// Destination context (same layoutId — motion handles the transition)
<motion.img layoutId="hero-image" src={src} className="w-full rounded-xl" />

Accordion

<motion.div
  initial={false}
  animate={{ opacity: open ? 1 : 0, scaleY: open ? 1 : 0 }}
  style={{ transformOrigin: "top", overflow: "hidden" }}
  transition={{
    duration: motionTokens.duration.normal,
    ease: motionTokens.easing.smooth,
  }}
> {children}
</motion.div>

End-to-End Example

A staggered list that enters on mount, handles conditional presence, and respects reduced motion — combining tokens, springs, AnimatePresence, and the accessibility hook from motion-foundations:

"use client"
import { useState } from "react"
import { motion, AnimatePresence } from "motion/react"
import { motionTokens, springs } from "@/lib/motion-tokens"
import { useSafeMotion } from "@/hooks/use-reduced-motion"

const containerVariants = {
  hidden: {},
  visible: {
    transition: { staggerChildren: 0.08, delayChildren: 0.1 },
  },
}

function ListItem({ label, onRemove }: { label: string; onRemove: () => void }) {
  const safe = useSafeMotion(motionTokens.distance.sm)
  return (
    <motion.li
      variants={{
        hidden:  safe.initial,
        visible: safe.animate,
      }}
      exit={safe.exit}
      transition={springs.gentle}
      className="flex items-center justify-between p-3 rounded-lg bg-white shadow-sm"
    >
      <span>{label}</span>
      <button onClick={onRemove}>Remove</button>
    </motion.li>
  )
}

export function AnimatedList({ items, onRemove }: {
  items: { id: string; label: string }[]
  onRemove: (id: string) => void
}) {
  return (
    <motion.ul
      variants={containerVariants}
      initial="hidden"
      animate="visible"
      className="space-y-2"
    >
      <AnimatePresence mode="popLayout">
        {items.map((item) => (
          <ListItem
            key={item.id}
            label={item.label}
            onRemove={() => onRemove(item.id)}
          />
        ))}
      </AnimatePresence>
    </motion.ul>
  )
}

Constraints / Non-Goals

This skill does not cover:

• Token and spring definitions → see motion-foundations
• Drag interactions, swipe gestures, reorderable lists → see motion-advanced
• Text animations (word/character reveal, counters) → see motion-advanced
• SVG path drawing or morphing → see motion-advanced
• Custom animation hooks → see motion-advanced
• CSS-only transitions not using motion/react

Anti-Patterns

Anti-pattern	Rule violated	Fix
AnimatePresence child missing key	Rule 1	Add stable key to the direct child
initial + animate without exit	Rule 2	Always define all three together
Page transition without mode="wait"	Rule 3	Add mode="wait" to AnimatePresence
layout on a 50-item list	Rule 4	Use mode="popLayout" or explicit transforms
staggerChildren: 0.2 on a 10-item list	Rule 5	Cap at 0.08–0.10
Modal without focus trap	Rule 6	Add focus-trap-react or Radix Dialog
whileInView without viewport={{ once: true }}	Rule 7	Repeating entrances distract, not inform
transition={{ duration: 0.3 }} inline	Rule 8	Use motionTokens.duration.normal

Related Skills

• motion-foundations — defines all tokens, springs, the useSafeMotion hook, and SSR guards that every pattern here imports. Must be set up first.
• motion-advanced — extends these patterns with drag, gestures, SVG, text, custom hooks, and imperative sequencing. Does not redefine any patterns from this skill.