/animate

Additional context needed: performance constraints.

Add motion that conveys state, gives feedback, and clarifies hierarchy. Cut motion that exists only for decoration. Animation fatigue is a real cost; spend the budget on the moments that need it.

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Register

Brand: motion is part of the voice; one well-rehearsed entrance beats scattered micro-interactions. The saturated AI default is fade-and-rise reveals on every scrolled section; that's a tell, not a choreography. Reserve scroll-triggered motion for moments that earn it.

Product: 150–250 ms on most transitions. Motion conveys state: feedback, reveal, loading, transitions between views. No page-load choreography; users are in a task and won't wait for it.

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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

2. 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, STOP and call the AskUserQuestion tool to clarify.

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.

Implement Animations

Add motion systematically across these categories:

Entrance Animations

• Hero section: Dramatic entrance for primary content (scale, parallax, or creative effects)

• Modal/drawer entry: Smooth slide + fade, backdrop fade, focus management

• List rhythm: Sibling stagger is legitimate for cards-in-a-grid or list-items-appearing. Whole-section fade-on-scroll is not a list and is not legitimate. Cap total stagger time: 10 items at 50ms each = 500ms total. For more items, reduce per-item delay or cap the staggered count.

  Use CSS custom properties for clean stagger: animation-delay: calc(var(--i, 0) * 50ms) with style="--i: 0", style="--i: 1", etc. on each item.

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

Duration: the 100/300/500 rule. Timing matters more than easing for "feels right":

Duration	Use Case	Examples
100–150ms	Instant feedback	Button press, toggle, color change
200–300ms	State changes	Menu open, tooltip, hover state
300–500ms	Layout changes	Accordion, modal, drawer
500–800ms	Entrance animations	Page load, hero reveal

Easing curves (use these, not CSS defaults):

/* Recommended: natural deceleration */
--ease-out-quart: cubic-bezier(0.25, 1, 0.5, 1);    /* Smooth */
--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 and opacity for reliable movement
- blur, filters, masks, clip paths, shadows, and color shifts for premium atmospheric effects when verified smooth

JavaScript Animation

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

Motion Materials

Transform and opacity are reliable defaults, not the whole palette. Premium interfaces often need atmospheric properties. Match material to effect:

• Transform / opacity: movement, press feedback, simple reveals, list choreography
• Blur / filter / backdrop-filter: focus pulls, depth, glass or lens effects, softened entrances
• Clip-path / masks: wipes, reveals, editorial cropping, product-like transitions
• Shadow / glow / color filters: energy, affordance, focus, warmth, active state
• Grid-template-rows or FLIP-style transforms: expanding and reflowing layout without animating height directly

The hard rule isn't "transform and opacity only." It's: avoid animating layout-driving properties casually (width, height, top, left, margins), keep expensive effects bounded to small or isolated areas, and verify smoothness in-browser on target viewports.

Performance

• Layout safety: Avoid casual animation of layout-driving properties (width, height, top, left, margins)
• will-change: Add sparingly for known expensive animations only (e.g. on :hover or an .animating class), never preemptively across the whole page
• Scroll triggers: Use Intersection Observer instead of scroll event listeners; unobserve after the animation fires once
• Bound expensive effects: Keep blur/filter/shadow areas small or isolated, use contain where appropriate
• Monitor FPS: Ensure 60fps on target devices

Perceived Performance

Nobody cares how fast your site is, only how fast it feels. The 80ms threshold: anything under ~80ms feels instant because our brains buffer sensory input for that long to synchronize perception. Target this for micro-interactions.

• Preemptive start: Begin transitions immediately while loading (iOS app zoom, skeleton UI). Users perceive work happening.
• Early completion: Show content progressively, don't wait for everything (progressive images, streaming HTML, skeleton fade-ins).
• Optimistic UI: Update the interface immediately, handle failures gracefully. Use for low-stakes actions (likes, follows). Avoid for payments or destructive operations.
• Easing affects perceived duration: Ease-in (accelerating toward completion) makes tasks feel shorter because the peak-end effect weights final moments heavily. Ease-out feels satisfying for entrances.
• Caution: Too-fast responses can decrease perceived value for complex operations (search, analysis). Sometimes a brief delay signals "real work" is happening.

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 casually (width, height, top, left, margins) when transform, FLIP, or grid-based techniques would work
• 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

When the motion clarifies state instead of decorating it, hand off to /impeccable polish for the final pass.