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

Duration	Use Case
100-150ms	Micro-feedback (hovers, clicks)
200-300ms	Small transitions (toggles, dropdowns)
300-500ms	Medium transitions (modals, page changes)
500ms+	Complex choreographed animations

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

Performance First: Use transform and opacity for smooth 60fps
Reduce Motion Support: Always respect prefers-reduced-motion
Consistent Timing: Use a timing scale across the app
Natural Physics: Prefer spring animations over linear
Interruptible: Allow users to cancel long animations
Progressive Enhancement: Work without JS animations
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

interaction-design