interaction-design

name: interaction-design
description: Design and implement microinteractions, motion design, transitions, and user feedback patterns. Use when adding polish to UI interactions, implementing loading states, or creating delightful user experiences.

Interaction Design

Create engaging, intuitive interactions through motion, feedback, and thoughtful state transitions that enhance usability and delight users.

When to Use This Skill

• Adding microinteractions to enhance user feedback
• Implementing smooth page and component transitions
• Designing loading states and skeleton screens
• Creating gesture-based interactions
• Building notification and toast systems
• Implementing drag-and-drop interfaces
• Adding scroll-triggered animations
• Designing hover and focus states

Core Principles

1. Purposeful Motion

Motion should communicate, not decorate:

• Feedback: Confirm user actions occurred
• Orientation: Show where elements come from/go to
• Focus: Direct attention to important changes
• Continuity: Maintain context during transitions

2. Timing Guidelines

3. Easing Functions

/* Common easings */
--ease-out: cubic-bezier(0.16, 1, 0.3, 1); /* Decelerate - entering */
--ease-in: cubic-bezier(0.55, 0, 1, 0.45); /* Accelerate - exiting */
--ease-in-out: cubic-bezier(0.65, 0, 0.35, 1); /* Both - moving between */
--spring: cubic-bezier(0.34, 1.56, 0.64, 1); /* Overshoot - playful */

Quick Start: Button Microinteraction

import { motion } from "framer-motion";

export function InteractiveButton({ children, onClick }) {
  return (
    <motion.button
      onClick={onClick}
      whileHover={{ scale: 1.02 }}
      whileTap={{ scale: 0.98 }}
      transition={{ type: "spring", stiffness: 400, damping: 17 }}
      className="px-4 py-2 bg-blue-600 text-white rounded-lg"
    >
      {children}
    </motion.button>
  );
}

Interaction Patterns

1. Loading States

Skeleton Screens: Preserve layout while loading

function CardSkeleton() {
  return (
    <div className="animate-pulse">
      <div className="h-48 bg-gray-200 rounded-lg" />
      <div className="mt-4 h-4 bg-gray-200 rounded w-3/4" />
      <div className="mt-2 h-4 bg-gray-200 rounded w-1/2" />
    </div>
  );
}

Progress Indicators: Show determinate progress

function ProgressBar({ progress }: { progress: number }) {
  return (
    <div className="h-2 bg-gray-200 rounded-full overflow-hidden">
      <motion.div
        className="h-full bg-blue-600"
        initial={{ width: 0 }}
        animate={{ width: `${progress}%` }}
        transition={{ ease: "easeOut" }}
      />
    </div>
  );
}

2. State Transitions

Toggle with smooth transition:

function Toggle({ checked, onChange }) {
  return (
    <button
      role="switch"
      aria-checked={checked}
      onClick={() => onChange(!checked)}
      className={`
        relative w-12 h-6 rounded-full transition-colors duration-200
        ${checked ? "bg-blue-600" : "bg-gray-300"}
      `}
    >
      <motion.span
        className="absolute top-1 left-1 w-4 h-4 bg-white rounded-full shadow"
        animate={{ x: checked ? 24 : 0 }}
        transition={{ type: "spring", stiffness: 500, damping: 30 }}
      />
    </button>
  );
}

3. Page Transitions

Framer Motion layout animations:

import { AnimatePresence, motion } from "framer-motion";

function PageTransition({ children, key }) {
  return (
    <AnimatePresence mode="wait">
      <motion.div
        key={key}
        initial={{ opacity: 0, y: 20 }}
        animate={{ opacity: 1, y: 0 }}
        exit={{ opacity: 0, y: -20 }}
        transition={{ duration: 0.3 }}
      >
        {children}
      </motion.div>
    </AnimatePresence>
  );
}

4. Feedback Patterns

Ripple effect on click:

function RippleButton({ children, onClick }) {
  const [ripples, setRipples] = useState([]);

  const handleClick = (e) => {
    const rect = e.currentTarget.getBoundingClientRect();
    const ripple = {
      x: e.clientX - rect.left,
      y: e.clientY - rect.top,
      id: Date.now(),
    };
    setRipples((prev) => [...prev, ripple]);
    setTimeout(() => {
      setRipples((prev) => prev.filter((r) => r.id !== ripple.id));
    }, 600);
    onClick?.(e);
  };

  return (
    <button onClick={handleClick} className="relative overflow-hidden">
      {children}
      {ripples.map((ripple) => (
        <span
          key={ripple.id}
          className="absolute bg-white/30 rounded-full animate-ripple"
          style={{ left: ripple.x, top: ripple.y }}
        />
      ))}
    </button>
  );
}

5. Gesture Interactions

Swipe to dismiss:

function SwipeCard({ children, onDismiss }) {
  return (
    <motion.div
      drag="x"
      dragConstraints={{ left: 0, right: 0 }}
      onDragEnd={(_, info) => {
        if (Math.abs(info.offset.x) > 100) {
          onDismiss();
        }
      }}
      className="cursor-grab active:cursor-grabbing"
    >
      {children}
    </motion.div>
  );
}

CSS Animation Patterns

Keyframe Animations

@keyframes fadeIn {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

@keyframes pulse {
  0%,
  100% {
    opacity: 1;
  }
  50% {
    opacity: 0.5;
  }
}

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

.animate-fadeIn {
  animation: fadeIn 0.3s ease-out;
}
.animate-pulse {
  animation: pulse 2s ease-in-out infinite;
}
.animate-spin {
  animation: spin 1s linear infinite;
}

CSS Transitions

.card {
  transition:
    transform 0.2s ease-out,
    box-shadow 0.2s ease-out;
}

.card:hover {
  transform: translateY(-4px);
  box-shadow: 0 12px 24px rgba(0, 0, 0, 0.1);
}

Accessibility Considerations

/* Respect user motion preferences */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
  }
}

function AnimatedComponent() {
  const prefersReducedMotion = window.matchMedia(
    "(prefers-reduced-motion: reduce)",
  ).matches;

  return (
    <motion.div
      animate={{ opacity: 1 }}
      transition={{ duration: prefersReducedMotion ? 0 : 0.3 }}
    />
  );
}

Best Practices

1. Performance First: Use transform and opacity for smooth 60fps
2. Reduce Motion Support: Always respect prefers-reduced-motion
3. Consistent Timing: Use a timing scale across the app
4. Natural Physics: Prefer spring animations over linear
5. Interruptible: Allow users to cancel long animations
6. Progressive Enhancement: Work without JS animations
7. Test on Devices: Performance varies significantly

Common Issues

• Janky Animations: Avoid animating width, height, top, left
• Over-animation: Too much motion causes fatigue
• Blocking Interactions: Never prevent user input during animations
• Memory Leaks: Clean up animation listeners on unmount
• Flash of Content: Use will-change sparingly for optimization