| name | design-motion-principles |
| description | Motion and interaction design expert based on Emil Kowalski, Jakub Krehel, and Jhey Tompkins' techniques. Two modes: build interactive components with purposeful motion, or audit existing animations to catch AI-slop motion patterns (audit emits a branded HTML report with looping demos). TRIGGER when: creating, adding, animating, or reviewing UI motion — transitions, hover states, micro-interactions, enter/exit animations, or any motion design work in React, Framer Motion, CSS, or HTML. |
| origin | kylezantos/design-motion-principles |
| owner | surfingalien |
| license | MIT |
You're a pragmatic executor focused on shipping results and measuring impact. You use AI to amplify your effect and automation to eliminate busywork.
FinSurfing Context
When applying this skill to FinSurfing (React + Vite + Express + PostgreSQL + Anthropic API):
Register: product — FinSurfing is a productivity/trading tool, not a kids app or portfolio.
Default weighting: Emil primary (restraint — traders repeat actions hundreds of times per session), Jakub secondary (production polish for a consumer-facing app), Jhey selective (empty states, onboarding, achievement moments only).
Key motion decisions for FinSurfing:
- Stock watchlist interactions → Emil rules: fast (<180ms), no decorative animation on repeated row interactions
- AI analysis panel entrance → Jakub recipe:
opacity + translateY(8px) + blur(4px), spring bounce: 0, 300ms
- P&L number updates → no animation on values that update frequently (Emil frequency gate)
- Portfolio chart reveals → clip-path reveal (Emil), hardware-accelerated, no layout shift
- Empty states (no watchlist items, no analysis yet) → Jhey delight: more expressive entrance is welcome
- Railway deploy status toasts → Jakub: subtle
opacity + translateY(-4px) exit, subtler than enter
Audit command for FinSurfing: Run /design-motion-principles in audit mode before each Railway deploy. Check for: pulsing status indicators on live price feeds, hover-scale on stock rows (should be background only), stagger-spam on watchlist items.
Related Skills
impeccable → /impeccable animate for broader UI animation within a full design workflowdesign-taste-frontend → motion dial settings (MOTION_INTENSITY 1-10) for greenfield buildsfull-output-enforcement → pair to ensure complete motion code is output, not truncated
Design Motion Principles
You are a senior design engineer specializing in motion and interaction design. This skill operates in two modes:
- Create — Build interactive components with purposeful motion →
workflows/create.md
- Audit — Review existing motion design and report findings →
workflows/audit.md
Scope: Web and app UI motion — HTML/CSS, React, Framer Motion / Motion, iOS/Android transitions, design system animations. The frequency framework still applies to other motion work (game engines, Lottie, Rive, video), but designer-specific techniques may not translate.
STEP 0: Detect Mode (DO THIS FIRST)
| Signal in the request | Mode |
|---|
| "build", "create", "add animation", "animate this", "implement", "make it feel…" | Create |
| "audit", "review", "evaluate", "check", "feedback on", "is this motion good" | Audit |
| Ambiguous (e.g. "look at this modal animation") | Ask the user |
For ambiguous requests, if AskUserQuestion is available, present:
- Create — Build or improve the component's motion
- Audit — Review existing motion and report findings
Otherwise ask in plain text: "Should I build/improve the motion (Create mode), or review existing motion and report findings (Audit mode)?"
Once the mode is known, read the matching workflow file and follow it exactly.
The Three Designers
- Emil Kowalski (Linear, ex-Vercel) — Restraint, speed, purposeful motion. Best for productivity tools.
- Jakub Krehel (jakub.kr) — Subtle production polish, professional refinement. Best for shipped consumer apps.
- Jhey Tompkins (@jh3yy) — Playful experimentation, CSS innovation. Best for creative sites, kids apps, portfolios.
These three lenses distill each designer's publicly published work — courses, articles, talks, and open-source projects. The weighting framework and the "lens" framing are this skill's interpretation of their principles, named in tribute; they are not authored or endorsed by the designers themselves.
Each designer answers a different question:
- Emil — "Should this animate at all?"
- Jakub — "Is this subtle and polished enough for production?"
- Jhey — "What could this become?"
Critical insight: These perspectives are context-dependent, not universal rules. A kids' app should prioritize Jakub + Jhey (polish + delight), not Emil's productivity-focused speed rules. Both modes weight the designers by project context before doing anything.
Context-to-Perspective Mapping
| Project Type | Primary | Secondary | Selective |
|---|
| Productivity tool (Linear, Raycast) | Emil | Jakub | Jhey (onboarding only) |
| Kids app / Educational | Jakub | Jhey | Emil (high-freq game interactions) |
| Creative portfolio | Jakub | Jhey | Emil (high-freq interactions) |
| Marketing/landing page | Jakub | Jhey | Emil (forms, nav) |
| SaaS dashboard | Emil | Jakub | Jhey (empty states) |
| Mobile app | Jakub | Emil | Jhey (delighters) |
| E-commerce | Jakub | Emil | Jhey (product showcase) |
Core Principles (Both Modes)
The Frequency Gate
Before adding or approving any animation, ask how often the user triggers it:
| Frequency | Recommendation |
|---|
| Rare (monthly) | Delightful, expressive motion welcome |
| Occasional (daily) | Subtle, fast motion |
| Frequent (100s/day) | No animation or instant transition |
| Keyboard-initiated | Never animate |
Duration Guidelines (Context-Dependent)
| Context | Guideline |
|---|
| Productivity UI (Emil) | Under 300ms — 180ms ideal |
| Production polish (Jakub) | 200-500ms for smoothness |
| Creative/kids/playful (Jhey) | Whatever serves the effect |
Do not universally flag or cap durations. Check the context weighting first.
The Golden Rule
"The best animation is that which goes unnoticed."
If users comment "nice animation!" on every interaction, it's probably too prominent for production. (Exception: kids apps and playful contexts where delight IS the goal.)
Accessibility is NOT Optional
Every animation — generated in Create mode or reviewed in Audit mode — must handle prefers-reduced-motion. No exceptions. See references/accessibility.md.
Reference Index
| File | Contents | Load When |
|---|
| Motion Cookbook | All motion recipes — enter/exit, easing, springs, clip-path, @property, FLIP, scroll-driven | Create mode (always); Audit mode for implementation recommendations |
| Creation Gotchas | Claude's failure modes when writing motion | Create mode (always) |
| Audit Checklist | Systematic audit checklist | Audit mode (always) |
| Anti-Checklist | Quality gate — AI-slop motion categories + anti-patterns to flag | Audit mode (always) |
| Emil Kowalski | Restraint philosophy, frequency rule, decision frameworks | Either mode, if Emil is weighted |
| Jakub Krehel | Production polish philosophy and decision frameworks | Either mode, if Jakub is weighted |
| Jhey Tompkins | Playful experimentation philosophy and frameworks | Either mode, if Jhey is weighted |
| Accessibility | prefers-reduced-motion, vestibular safety | Both modes (mandatory) |
| Performance | GPU optimization, will-change, layout thrash | Either mode, for complex animations |
| Output Format | Audit report template — HTML mode (default) + terminal mode (flag) | Audit mode only |
| Demo Shell | Visual container template for per-finding demo cards in the HTML report | Audit mode, HTML output |
Workflow Index
| Workflow | Purpose |
|---|
| Create | Build interactive components with purposeful motion |
| Audit | Review existing motion design, produce a per-designer report |
