AgentSkillsCN

animator

适用于网页界面的动画与微交互模式。在为 UI 组件添加过渡效果、动画、悬停特效、加载状态,或任何动态效果时使用。

SKILL.md
--- frontmatter
name: animator
description: Animation and micro-interaction patterns for web interfaces. Use when adding transitions, animations, hover effects, loading states, or any motion to UI components.

Motion Design

Create meaningful, performant animations that enhance user experience.

Core Principles

Purpose of Motion

  • Feedback - Confirm user actions (button press, form submit)
  • Orientation - Show where elements come from/go to
  • Focus - Direct attention to important changes
  • Delight - Add personality without slowing users down

When NOT to Animate

  • User has prefers-reduced-motion enabled
  • Animation would delay critical actions
  • Motion doesn't add meaning
  • On low-powered devices
css
@media (prefers-reduced-motion: reduce) {
  *, *::before, *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
  }
}

Timing & Easing

Duration Guidelines

TypeDurationUse Case
Micro100-150msButton states, toggles, small feedback
Standard200-300msMost UI transitions, modals, dropdowns
Complex300-500msPage transitions, large reveals
Emphasis500ms+Onboarding, celebrations (use sparingly)

Easing Functions

css
/* Natural motion - use for most UI */
--ease-out: cubic-bezier(0.0, 0.0, 0.2, 1);      /* Decelerate */
--ease-in: cubic-bezier(0.4, 0.0, 1, 1);          /* Accelerate */
--ease-in-out: cubic-bezier(0.4, 0.0, 0.2, 1);   /* Both */

/* Expressive motion - entrances/exits */
--ease-spring: cubic-bezier(0.175, 0.885, 0.32, 1.275);  /* Overshoot */
--ease-bounce: cubic-bezier(0.68, -0.55, 0.265, 1.55);   /* Playful */

/* Quick reference */
ease-out: Elements entering (coming to rest)
ease-in: Elements exiting (accelerating away)
ease-in-out: Elements moving between states

Tailwind Defaults

html
<!-- Duration -->
duration-75 duration-100 duration-150 duration-200 duration-300 duration-500

<!-- Easing -->
ease-linear ease-in ease-out ease-in-out

Common Patterns

Button Interactions

css
.button {
  transition: transform 150ms ease-out,
              box-shadow 150ms ease-out,
              background-color 150ms ease-out;
}

.button:hover {
  transform: translateY(-1px);
  box-shadow: 0 4px 12px rgba(0, 0, 0, 0.15);
}

.button:active {
  transform: translateY(0) scale(0.98);
  box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}
tsx
// Tailwind
<button className="transition-all duration-150 ease-out
  hover:-translate-y-0.5 hover:shadow-lg
  active:translate-y-0 active:scale-[0.98]">
  Click me
</button>

Fade & Scale Enter

css
/* Modal/Dialog entrance */
@keyframes fadeScaleIn {
  from {
    opacity: 0;
    transform: scale(0.95);
  }
  to {
    opacity: 1;
    transform: scale(1);
  }
}

.modal {
  animation: fadeScaleIn 200ms ease-out;
}

Slide Transitions

css
/* Slide from bottom */
@keyframes slideUp {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Slide from side (for drawers) */
@keyframes slideInRight {
  from { transform: translateX(100%); }
  to { transform: translateX(0); }
}

Staggered List Animation

tsx
// Framer Motion
<motion.ul>
  {items.map((item, i) => (
    <motion.li
      key={item.id}
      initial={{ opacity: 0, y: 20 }}
      animate={{ opacity: 1, y: 0 }}
      transition={{ delay: i * 0.05 }}
    />
  ))}
</motion.ul>
css
/* CSS stagger with animation-delay */
.list-item {
  opacity: 0;
  animation: fadeSlideIn 300ms ease-out forwards;
}

.list-item:nth-child(1) { animation-delay: 0ms; }
.list-item:nth-child(2) { animation-delay: 50ms; }
.list-item:nth-child(3) { animation-delay: 100ms; }
/* ... or use CSS custom properties */

.list-item {
  animation-delay: calc(var(--index) * 50ms);
}

Loading States

css
/* Pulse (skeleton loading) */
@keyframes pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.5; }
}

.skeleton {
  animation: pulse 2s ease-in-out infinite;
}

/* Spinner */
@keyframes spin {
  to { transform: rotate(360deg); }
}

.spinner {
  animation: spin 1s linear infinite;
}

/* Progress bar shimmer */
@keyframes shimmer {
  0% { background-position: -200% 0; }
  100% { background-position: 200% 0; }
}

.shimmer {
  background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
  background-size: 200% 100%;
  animation: shimmer 1.5s infinite;
}

Hover Reveals

css
/* Image zoom on hover */
.image-container {
  overflow: hidden;
}

.image-container img {
  transition: transform 300ms ease-out;
}

.image-container:hover img {
  transform: scale(1.05);
}

/* Underline grow */
.link {
  position: relative;
}

.link::after {
  content: '';
  position: absolute;
  bottom: 0;
  left: 0;
  width: 100%;
  height: 2px;
  background: currentColor;
  transform: scaleX(0);
  transform-origin: right;
  transition: transform 250ms ease-out;
}

.link:hover::after {
  transform: scaleX(1);
  transform-origin: left;
}

Framer Motion Patterns

Basic Animation

tsx
import { motion } from 'framer-motion';

<motion.div
  initial={{ opacity: 0, y: 20 }}
  animate={{ opacity: 1, y: 0 }}
  exit={{ opacity: 0, y: -20 }}
  transition={{ duration: 0.2, ease: 'easeOut' }}
>
  Content
</motion.div>

Variants for Complex Animations

tsx
const containerVariants = {
  hidden: { opacity: 0 },
  visible: {
    opacity: 1,
    transition: {
      staggerChildren: 0.05,
    },
  },
};

const itemVariants = {
  hidden: { opacity: 0, y: 20 },
  visible: { opacity: 1, y: 0 },
};

<motion.ul variants={containerVariants} initial="hidden" animate="visible">
  {items.map((item) => (
    <motion.li key={item.id} variants={itemVariants}>
      {item.name}
    </motion.li>
  ))}
</motion.ul>

Layout Animations

tsx
// Animate layout changes automatically
<motion.div layout>
  {isExpanded ? <ExpandedContent /> : <CollapsedContent />}
</motion.div>

// Shared layout animation (element morphing)
<motion.div layoutId="shared-element">
  {/* This element animates between positions */}
</motion.div>

Gestures

tsx
<motion.button
  whileHover={{ scale: 1.05 }}
  whileTap={{ scale: 0.95 }}
  transition={{ type: 'spring', stiffness: 400, damping: 17 }}
>
  Press me
</motion.button>

AnimatePresence for Exit Animations

tsx
import { AnimatePresence, motion } from 'framer-motion';

<AnimatePresence mode="wait">
  {isVisible && (
    <motion.div
      key="modal"
      initial={{ opacity: 0 }}
      animate={{ opacity: 1 }}
      exit={{ opacity: 0 }}
    >
      Modal content
    </motion.div>
  )}
</AnimatePresence>

GSAP Patterns

Basic Animation

tsx
import gsap from 'gsap';

// Simple tween
gsap.to('.element', {
  x: 100,
  opacity: 1,
  duration: 0.3,
  ease: 'power2.out'
});

// From animation
gsap.from('.element', {
  y: 20,
  opacity: 0,
  duration: 0.3,
  ease: 'power2.out'
});

Timeline for Sequences

tsx
const tl = gsap.timeline();

tl.from('.header', { y: -50, opacity: 0 })
  .from('.content', { y: 20, opacity: 0 }, '-=0.2')
  .from('.footer', { y: 20, opacity: 0 }, '-=0.2');

// Control the timeline
tl.play();
tl.pause();
tl.reverse();

Stagger Animations

tsx
gsap.from('.list-item', {
  y: 20,
  opacity: 0,
  duration: 0.3,
  stagger: 0.05,
  ease: 'power2.out'
});

ScrollTrigger

tsx
import { ScrollTrigger } from 'gsap/ScrollTrigger';
gsap.registerPlugin(ScrollTrigger);

gsap.from('.section', {
  scrollTrigger: {
    trigger: '.section',
    start: 'top 80%',
    end: 'bottom 20%',
    toggleActions: 'play none none reverse'
  },
  y: 50,
  opacity: 0,
  duration: 0.6
});

GSAP Easing

tsx
// Power easings (1-4, higher = more dramatic)
ease: 'power1.out'  // Subtle
ease: 'power2.out'  // Standard (like ease-out)
ease: 'power3.out'  // Pronounced
ease: 'power4.out'  // Dramatic

// Special easings
ease: 'back.out(1.7)'   // Overshoot
ease: 'elastic.out(1, 0.3)'  // Bouncy
ease: 'bounce.out'      // Bounce at end

React Integration

tsx
import { useGSAP } from '@gsap/react';
import gsap from 'gsap';

function Component() {
  const containerRef = useRef(null);

  useGSAP(() => {
    gsap.from('.item', {
      y: 20,
      opacity: 0,
      stagger: 0.1
    });
  }, { scope: containerRef });

  return (
    <div ref={containerRef}>
      <div className="item">Item 1</div>
      <div className="item">Item 2</div>
    </div>
  );
}

Performance Tips

Use Transform & Opacity

css
/* Good - GPU accelerated */
transform: translateX(100px);
transform: scale(1.1);
transform: rotate(45deg);
opacity: 0.5;

/* Avoid animating - triggers layout */
width, height, top, left, margin, padding

will-change Hint

css
/* Use sparingly - only for known animations */
.animated-element {
  will-change: transform, opacity;
}

/* Remove after animation */
.animated-element.done {
  will-change: auto;
}

Reduce Motion Query

tsx
// React hook
const prefersReducedMotion = window.matchMedia(
  '(prefers-reduced-motion: reduce)'
).matches;

// Framer Motion
<motion.div
  animate={{ x: 100 }}
  transition={{
    duration: prefersReducedMotion ? 0 : 0.3
  }}
/>

Quick Reference

ElementDurationEasingProperties
Button hover150msease-outtransform, shadow, bg
Toggle switch200msease-outtransform
Dropdown open200msease-outopacity, transform
Modal enter250msease-outopacity, scale
Modal exit200msease-inopacity, scale
Page transition300msease-in-outopacity, transform
Toast enter300msspringtransform
Skeleton pulse2000msease-in-outopacity

Motion Checklist

  • Animation has clear purpose (feedback, orientation, focus)
  • Duration feels snappy (not sluggish)
  • Easing matches motion type (ease-out for enters)
  • Respects prefers-reduced-motion
  • Only animates transform/opacity when possible
  • Exit animations are faster than enters
  • Stagger delays are subtle (30-50ms)
  • No animation blocks user interaction