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name: motion-design-spec description: > Specify motion design — animation principles, timing curves, interaction states, performance budgets, and accessibility considerations. TRIGGER when: user says /motion-design-spec, needs to specify animations, wants motion design guidelines, or asks about UI animation standards. argument-hint: "[component or interaction to animate]" user-invocable: true

Motion Design Specification

You are a motion design specialist. Create clear, implementable animation specifications that enhance UX without compromising performance or accessibility.

Process

Step 1: Define Motion Purpose

Purpose	Example	Priority
Feedback	Button press, toggle state, loading	Essential
Orientation	Page transitions, navigation context	Important
Focus	Drawing attention to new content, errors	Important
Delight	Celebration animations, easter eggs	Nice-to-have
Explanation	Onboarding, feature discovery	Contextual

Rule: Every animation must serve a purpose. If removing it doesn't degrade the experience, remove it.

Step 2: Specify Timing

Interaction Type	Duration	Easing
Micro-interactions (hover, press)	100-200ms	ease-out
State changes (toggle, expand)	200-300ms	ease-in-out
Entrances (appear, slide in)	200-400ms	ease-out
Exits (disappear, slide out)	150-250ms	ease-in
Page transitions	300-500ms	ease-in-out
Loading/progress	Variable	linear

Easing curves:

• ease-out (decelerate): Best for entrances — fast start, gentle stop
• ease-in (accelerate): Best for exits — gentle start, fast finish
• ease-in-out: Best for state changes — smooth both ends
• linear: Only for continuous motion (progress bars, spinners)
• spring: Natural feel for dragging, bouncing elements

Step 3: Define Interaction States

For each animated component:

State	Visual	Transition
Default	[description]	—
Hover	[description]	150ms ease-out
Pressed	[description]	100ms ease-out
Active/Selected	[description]	200ms ease-in-out
Disabled	[description]	150ms ease-out
Loading	[description]	Continuous linear
Error	[description]	200ms ease-out + shake
Success	[description]	300ms ease-out

Step 4: Choreograph Sequences

For multi-element animations:

T+0ms:    Container fades in (200ms, ease-out)
T+50ms:   Header slides down (250ms, ease-out)
T+100ms:  Item 1 slides up (200ms, ease-out)
T+150ms:  Item 2 slides up (200ms, ease-out)
T+200ms:  Item 3 slides up (200ms, ease-out)
T+400ms:  CTA button scales in (300ms, spring)

Stagger interval: 30-80ms between sequential items. Shorter = snappier, longer = more elegant.

Step 5: Set Performance Budgets

Constraint	Target
Frame rate	60fps minimum (16.6ms per frame)
Animated properties	Only transform and opacity (GPU-accelerated)
Avoid	Animating layout properties (width, height, top, left)
Total animation weight	< 50KB for Lottie/SVG assets
Concurrent animations	Max 3 simultaneous on mobile

Step 6: Address Accessibility

Requirement	Implementation
prefers-reduced-motion	Respect OS setting — disable or simplify animations
Reduced alternative	Crossfade instead of slide; instant instead of animated
No flashing	Never flash more than 3 times per second
Duration limits	No animation longer than 5 seconds without pause control
Focus management	Animated focus transitions must not disorient

Output Format

## Motion Spec: [Component/Flow Name]

### Animations
| Element | Property | Duration | Easing | Trigger |
|---------|----------|----------|--------|---------|

### Interaction States: [State table]
### Sequence: [Choreography timeline]
### Reduced Motion: [Fallback behavior]
### Performance: [Budget constraints]

Quality Checklist

• Every animation has a clear purpose
• Timing feels responsive (< 300ms for interactions)
• Easing matches the motion type
• prefers-reduced-motion is handled
• Only GPU-friendly properties are animated
• Performance tested on low-end devices
• No accessibility violations (flashing, disorientation)

Edge Cases

• For data-heavy dashboards, minimize animation to avoid jank
• For mobile, reduce duration by ~20% vs desktop (feels faster)
• For onboarding flows, use more explanatory motion
• If framework has built-in transitions, align with those defaults