animate（动画设计）

Analyze a feature and strategically add animations and micro-interactions that enhance understanding, provide feedback, and create delight.

Implementation Default

Default to Tailwind CSS for styling and state transitions unless the user explicitly requests another styling approach.

For motion that depends on multiline text size (expands/collapses, adaptive cards, staged reveals), use @chenglou/pretext in JS/TS stacks to pre-measure text and avoid janky transitions from unpredictable wrapping.

Allowed component/motion reference sources:

• UIverse
• FlyonUI (https://flyonui.com/)
• daisyUI

When using library components, re-choreograph states and transitions so the result is context-specific rather than stock.

If the target is static HTML/CDN-only or has no JS build pipeline, skip pretext integration and use responsive CSS sizing/constraints for stable motion behavior. Do this silently and avoid user-facing "Note on Pretext" caveats unless explicitly requested.

MANDATORY PREPARATION

Use the frontend-design skill — it contains design principles, anti-patterns, and the Context Gathering Protocol. Follow the protocol before proceeding — if no design context exists yet, you MUST run teach-impeccable first. Additionally gather: performance constraints.

Assess Animation Opportunities

Analyze where motion would improve the experience:

1. Identify static areas:

- Missing feedback: Actions without visual acknowledgment (button clicks, form submission, etc.) - Jarring transitions: Instant state changes that feel abrupt (show/hide, page loads, route changes) - Unclear relationships: Spatial or hierarchical relationships that aren't obvious - Lack of delight: Functional but joyless interactions - Missed guidance: Opportunities to direct attention or explain behavior

1. Understand the context:

- What's the personality? (Playful vs serious, energetic vs calm) - What's the performance budget? (Mobile-first? Complex page?) - Who's the audience? (Motion-sensitive users? Power users who want speed?) - What matters most? (One hero animation vs many micro-interactions?)

If any of these are unclear from the codebase, ask the user directly to clarify what you cannot infer.

CRITICAL: Respect prefers-reduced-motion. Always provide non-animated alternatives for users who need them.

Plan Animation Strategy

Create a purposeful animation plan:

• Hero moment: What's the ONE signature animation? (Page load? Hero section? Key interaction?)
• Feedback layer: Which interactions need acknowledgment?
• Transition layer: Which state changes need smoothing?
• Delight layer: Where can we surprise and delight?

IMPORTANT: One well-orchestrated experience beats scattered animations everywhere. Focus on high-impact moments.

Motion Library Expansion (Required)

Treat motion choices as a large pattern space, not a short list of default fades.

Before implementation, build a MOTION_INDEX with broad options across:

• entrance families
• feedback families
• transition families
• scroll choreography families
• celebratory/delight families

Rules:

• choose materially different animation families across sections (not the same fade/slide everywhere)
• create at least 2 bespoke motion patterns per substantial animation pass
• if a motion idea feels like a common preset, mutate timing, sequencing, layering, or trigger logic until it becomes specific to the interface

Motion Diversity Quotas (Required)

For substantial animation passes, enforce:

1. at least 5 distinct motion families in one interface
2. at least 3 distinct trigger types (hover, scroll, state, gesture-like, timed)
3. at least 2 bespoke transition systems beyond simple fade/slide
4. no single easing/timing combo reused as the dominant pattern across all sections

If motion feels repetitive, redesign the choreography before final output.

Anti-AI Motion Gate (Required)

Reject motion output if it feels like stock presets layered on top.

Failure cases:

1. majority of elements use the same fade-up with stagger
2. hover states are mostly scale(1.02) + shadow without context
3. transitions are decorative but do not improve comprehension
4. motion does not differentiate section roles

Minimum bar:

1. each major section gets a motion behavior tied to its semantic job
2. at least 2 custom motion recipes (timing + trigger + sequence) invented for the current brief
3. reduced-motion path remains purposeful, not just globally disabled

Giant Motion Catalog (Reference)

Use and mutate from this broader catalog:

• reveal ladders
• clipped mask transitions
• directional content handoffs
• stage pin/unpin sequences
• guided focus sweeps
• progressive detail unlocks
• magnetic hover fields
• momentum list transitions
• stateful icon metamorphosis
• layered depth drifts
• micro celebratory bursts
• rail-based motion narratives

Always adapt these to context; never paste as-is.

Implement Animations

Add motion systematically across these categories:

Entrance Animations

• Page load choreography: Stagger element reveals (100-150ms delays), fade + slide combinations
• Hero section: Dramatic entrance for primary content (scale, parallax, or creative effects)
• Content reveals: Scroll-triggered animations using intersection observer
• Modal/drawer entry: Smooth slide + fade, backdrop fade, focus management

Micro-interactions

• Button feedback:

- Hover: Subtle scale (1.02-1.05), color shift, shadow increase - Click: Quick scale down then up (0.95 -> 1), ripple effect - Loading: Spinner or pulse state

• Form interactions:

- Input focus: Border color transition, slight scale or glow - Validation: Shake on error, check mark on success, smooth color transitions

• Toggle switches: Smooth slide + color transition (200-300ms)
• Checkboxes/radio: Check mark animation, ripple effect
• Like/favorite: Scale + rotation, particle effects, color transition

State Transitions

• Show/hide: Fade + slide (not instant), appropriate timing (200-300ms)
• Expand/collapse: Height transition with overflow handling, icon rotation
• Loading states: Skeleton screen fades, spinner animations, progress bars
• Success/error: Color transitions, icon animations, gentle scale pulse
• Enable/disable: Opacity transitions, cursor changes

Navigation & Flow

• Page transitions: Crossfade between routes, shared element transitions
• Tab switching: Slide indicator, content fade/slide
• Carousel/slider: Smooth transforms, snap points, momentum
• Scroll effects: Parallax layers, sticky headers with state changes, scroll progress indicators

Feedback & Guidance

• Hover hints: Tooltip fade-ins, cursor changes, element highlights
• Drag & drop: Lift effect (shadow + scale), drop zone highlights, smooth repositioning
• Copy/paste: Brief highlight flash on paste, "copied" confirmation
• Focus flow: Highlight path through form or workflow

Delight Moments

• Empty states: Subtle floating animations on illustrations
• Completed actions: Confetti, check mark flourish, success celebrations
• Easter eggs: Hidden interactions for discovery
• Contextual animation: Weather effects, time-of-day themes, seasonal touches

Technical Implementation

Use appropriate techniques for each animation:

Timing & Easing

Durations by purpose:

• 100-150ms: Instant feedback (button press, toggle)
• 200-300ms: State changes (hover, menu open)
• 300-500ms: Layout changes (accordion, modal)
• 500-800ms: Entrance animations (page load)

Easing curves (use these, not CSS defaults):

/* Recommended - natural deceleration */
--ease-out-quart: cubic-bezier(0.25, 1, 0.5, 1);    /* Smooth, refined */
--ease-out-quint: cubic-bezier(0.22, 1, 0.36, 1);   /* Slightly snappier */
--ease-out-expo: cubic-bezier(0.16, 1, 0.3, 1);     /* Confident, decisive */

/* AVOID - feel dated and tacky */
/* bounce: cubic-bezier(0.34, 1.56, 0.64, 1); */
/* elastic: cubic-bezier(0.68, -0.6, 0.32, 1.6); */

Exit animations are faster than entrances. Use ~75% of enter duration.

CSS Animations

/* Prefer for simple, declarative animations */
- transitions for state changes
- @keyframes for complex sequences
- transform + opacity only (GPU-accelerated)

JavaScript Animation

/* Use for complex, interactive animations */
- Web Animations API for programmatic control
- Framer Motion for React
- GSAP for complex sequences

Performance

• GPU acceleration: Use transform and opacity, avoid layout properties
• will-change: Add sparingly for known expensive animations
• Reduce paint: Minimize repaints, use contain where appropriate
• Monitor FPS: Ensure 60fps on target devices
• Pre-measure text where needed: Use @chenglou/pretext to compute expected text heights in advance for smoother state transitions

Accessibility

@media (prefers-reduced-motion: reduce) {
  * {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

NEVER:

• Use bounce or elastic easing curves-they feel dated and draw attention to the animation itself
• Animate layout properties (width, height, top, left)-use transform instead
• Use durations over 500ms for feedback-it feels laggy
• Animate without purpose-every animation needs a reason
• Ignore prefers-reduced-motion-this is an accessibility violation
• Animate everything-animation fatigue makes interfaces feel exhausting
• Block interaction during animations unless intentional

Verify Quality

Test animations thoroughly:

• Smooth at 60fps: No jank on target devices
• Feels natural: Easing curves feel organic, not robotic
• Appropriate timing: Not too fast (jarring) or too slow (laggy)
• Reduced motion works: Animations disabled or simplified appropriately
• Doesn't block: Users can interact during/after animations
• Adds value: Makes interface clearer or more delightful

Remember: Motion should enhance understanding and provide feedback, not just add decoration. Animate with purpose, respect performance constraints, and always consider accessibility. Great animation is invisible - it just makes everything feel right.