gsap-framer-scroll-animation

# GSAP & Framer Motion — Scroll Animations Skill

Production-grade scroll animations with GitHub Copilot prompts, ready-to-use code recipes, and deep API references.

> **Design Companion:** This skill provides the *technical implementation* for scroll-driven motion.
> For the *creative philosophy*, design principles, and premium aesthetics that should guide **how**
> and **when** to animate, always cross-reference the **premium-frontend-ui** skill.
> Together they form a complete approach: premium-frontend-ui decides the **what** and **why**;
> this skill delivers the **how**.

## Quick Library Selector

| Need | Use |
|---|---|
| Vanilla JS, Webflow, Vue | **GSAP** |
| Pinning, horizontal scroll, complex timelines | **GSAP** |
| React / Next.js, declarative style | **Framer Motion** |
| whileInView entrance animations | **Framer Motion** |
| Both in same Next.js app | See notes in references |

Read the relevant reference file for full recipes and Copilot prompts:

- **GSAP** → `references/gsap.md` — ScrollTrigger API, all recipes, React integration
- **Framer Motion** → `references/framer.md` — useScroll, useTransform, all recipes

## Setup (Always Do First)

### GSAP
```bash
npm install gsap
```
```js
import gsap from 'gsap';
import { ScrollTrigger } from 'gsap/ScrollTrigger';
gsap.registerPlugin(ScrollTrigger); // MUST call before any ScrollTrigger usage
```

### Framer Motion (Motion v12, 2025)
```bash
npm install motion   # new package name since mid-2025
# or: npm install framer-motion  — still works, same API
```
```js
import { motion, useScroll, useTransform, useSpring } from 'motion/react';
// legacy: import { motion } from 'framer-motion'  — also valid
```

## Workflow

1. Interpret the user's intent to identify if GSAP or Framer Motion is the best fit.
2. Read the relevant reference document in `references/` for detailed APIs and patterns.
3. Suggest the required package installation if not already present.
4. Implement the scaffold for the animation structure, adhering to the requested format (React components, hook requirements, or vanilla JS).
5. Apply the correct tools (scrolling vs in-view elements) ensuring accessibility options are present and hooks don't cause infinite re-renders.

## The 5 Most Common Scroll Patterns

Quick reference — full recipes with Copilot prompts are in the reference files.

### 1. Fade-in on enter (GSAP)
```js
gsap.from('.card', {
  opacity: 0, y: 50, stagger: 0.15, duration: 0.8,
  scrollTrigger: { trigger: '.card', start: 'top 85%' }
});
```

### 2. Fade-in on enter (Framer Motion)
```jsx
<motion.div
  initial={{ opacity: 0, y: 40 }}
  whileInView={{ opacity: 1, y: 0 }}
  viewport={{ once: true, margin: '-80px' }}
  transition={{ duration: 0.6 }}
/>
```

### 3. Scrub / scroll-linked (GSAP)
```js
gsap.to('.hero-img', {
  scale: 1.3, opacity: 0, ease: 'none',
  scrollTrigger: { trigger: '.hero', start: 'top top', end: 'bottom top', scrub: true }
});
```

### 4. Scroll-linked (Framer Motion)
```jsx
const { scrollYProgress } = useScroll({ target: ref, offset: ['start end', 'end start'] });
const y = useTransform(scrollYProgress, [0, 1], [0, -100]);
return <motion.div style={{ y }} />;
```

### 5. Pinned timeline (GSAP)
```js
const tl = gsap.timeline({
  scrollTrigger: { trigger: '.section', pin: true, scrub: 1, start: 'top top', end: '+=200%' }
});
tl.from('.title', { opacity: 0, y: 60 }).from('.img', { scale: 0.85 });
```

## Critical Rules (Apply Always)

- **GSAP**: always call `gsap.registerPlugin(ScrollTrigger)` before using it
- **GSAP scrub**: always use `ease: 'none'` — easing feels wrong when scrub is active
- **GSAP React**: use `useGSAP` from `@gsap/react`, never plain `useEffect` — it auto-cleans ScrollTriggers
- **GSAP debug**: add `markers: true` during development; remove before production
- **Framer**: `useTransform` output must go into `style` prop of a `motion.*` element, not a plain div
- **Framer Next.js**: always add `'use client'` at top of any file using motion hooks
- **Both**: animate only `transform` and `opacity` — avoid `width`, `height`, `box-shadow`
- **Accessibility**: always check `prefers-reduced-motion` — see each reference file for patterns
- **Premium polish**: follow the **premium-frontend-ui** skill principles for motion timing, easing curves, and restraint — animation should enhance, never overwhelm

## Copilot Prompting Tips

- Give Copilot the full selector, base image, and scroll range upfront — vague prompts produce vague code
- For GSAP, always specify: selector, start/end strings, whether you want scrub or toggleActions
- For Framer, always specify: which hook (useScroll vs whileInView), offset values, what to transform
- Paste the exact error message when asking `/fix` — Copilot fixes are dramatically better with real errors
- Use `@workspace` scope in Copilot Chat so it reads your existing component structure

## Reference Files

| File | Contents |
|---|---|
| `references/gsap.md` | Full ScrollTrigger API reference, 10 recipes, React (useGSAP), Lenis, matchMedia, accessibility |
| `references/framer.md` | Full useScroll / useTransform API, 8 recipes, variants, Motion v12 notes, Next.js tips |

## Related Skills

| Skill | Relationship |
|---|---|
| **premium-frontend-ui** | Creative philosophy, design principles, and aesthetic guidelines — defines *when* and *why* to animate |