---

name: responsive-design-advisor description: Design responsive layouts with breakpoints, mobile-first approach, and flexible grids. Use when creating responsive designs, implementing breakpoints, or optimizing for multiple screen sizes.

Responsive Design Advisor

Design responsive layouts that work across all device sizes.

Quick Start

Use mobile-first approach, flexible units (rem, %), CSS Grid/Flexbox, and test on real devices.

Instructions

Mobile-First Approach

Start with mobile, enhance for larger screens:

Copy/* Base styles (mobile) */
.container {
  padding: 1rem;
}

/* Tablet */
@media (min-width: 768px) {
  .container {
    padding: 2rem;
  }
}

/* Desktop */
@media (min-width: 1024px) {
  .container {
    padding: 3rem;
    max-width: 1200px;
    margin: 0 auto;
  }
}

Common Breakpoints

Standard breakpoints:

Copy/* Mobile: 0-639px (default) */

/* Tablet: 640px+ */
@media (min-width: 640px) { }

/* Laptop: 1024px+ */
@media (min-width: 1024px) { }

/* Desktop: 1280px+ */
@media (min-width: 1280px) { }

/* Large: 1536px+ */
@media (min-width: 1536px) { }

Tailwind breakpoints:

Copy<div className="
  w-full          // Mobile
  md:w-1/2        // Tablet
  lg:w-1/3        // Desktop
">
  Content
</div>

Flexible Layouts

CSS Grid:

Copy.grid {
  display: grid;
  gap: 1rem;
  
  /* Mobile: 1 column */
  grid-template-columns: 1fr;
}

@media (min-width: 768px) {
  .grid {
    /* Tablet: 2 columns */
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .grid {
    /* Desktop: 3 columns */
    grid-template-columns: repeat(3, 1fr);
  }
}

Auto-fit grid:

Copy.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
  gap: 1rem;
}

Flexbox:

Copy.flex-container {
  display: flex;
  flex-wrap: wrap;
  gap: 1rem;
}

.flex-item {
  flex: 1 1 100%; /* Mobile: full width */
}

@media (min-width: 768px) {
  .flex-item {
    flex: 1 1 calc(50% - 0.5rem); /* Tablet: 2 columns */
  }
}

@media (min-width: 1024px) {
  .flex-item {
    flex: 1 1 calc(33.333% - 0.667rem); /* Desktop: 3 columns */
  }
}

Responsive Typography

Fluid typography:

Copyh1 {
  font-size: clamp(2rem, 5vw, 4rem);
}

p {
  font-size: clamp(1rem, 2vw, 1.125rem);
}

Responsive scale:

Copy/* Mobile */
h1 { font-size: 2rem; }
h2 { font-size: 1.5rem; }
p { font-size: 1rem; }

/* Desktop */
@media (min-width: 1024px) {
  h1 { font-size: 3rem; }
  h2 { font-size: 2rem; }
  p { font-size: 1.125rem; }
}

Responsive Images

Responsive image:

Copyimg {
  max-width: 100%;
  height: auto;
}

Art direction:

Copy<picture>
  <source
    media="(min-width: 1024px)"
    srcSet="desktop.jpg"
  />
  <source
    media="(min-width: 768px)"
    srcSet="tablet.jpg"
  />
  <img src="mobile.jpg" alt="Description" />
</picture>

Responsive background:

Copy.hero {
  background-image: url('mobile.jpg');
}

@media (min-width: 768px) {
  .hero {
    background-image: url('tablet.jpg');
  }
}

@media (min-width: 1024px) {
  .hero {
    background-image: url('desktop.jpg');
  }
}

Container Queries

Component-based responsive:

Copy.card-container {
  container-type: inline-size;
}

.card {
  padding: 1rem;
}

@container (min-width: 400px) {
  .card {
    display: grid;
    grid-template-columns: 1fr 2fr;
  }
}

Navigation Patterns

Mobile menu:

Copyfunction Navigation() {
  const [isOpen, setIsOpen] = useState(false);
  
  return (
    <nav>
      {/* Mobile: Hamburger */}
      <button
        className="md:hidden"
        onClick={() => setIsOpen(!isOpen)}
      >
        Menu
      </button>
      
      {/* Mobile: Drawer */}
      <div className={`
        fixed inset-0 bg-white transform transition-transform
        ${isOpen ? 'translate-x-0' : '-translate-x-full'}
        md:relative md:translate-x-0
      `}>
        <ul className="flex flex-col md:flex-row">
          <li>Home</li>
          <li>About</li>
          <li>Contact</li>
        </ul>
      </div>
    </nav>
  );
}

Touch Targets

Minimum size:

Copybutton, a {
  min-height: 44px; /* iOS recommendation */
  min-width: 44px;
  padding: 0.75rem 1rem;
}

Touch-friendly spacing:

Copy.button-group button {
  margin: 0.5rem; /* Space between touch targets */
}

Viewport Units

Full height:

Copy.hero {
  height: 100vh; /* Viewport height */
  height: 100dvh; /* Dynamic viewport (mobile) */
}

Responsive spacing:

Copy.section {
  padding: 5vw; /* Scales with viewport */
}

Common Patterns

Sidebar layout:

Copy.layout {
  display: grid;
  gap: 2rem;
  
  /* Mobile: Stack */
  grid-template-columns: 1fr;
}

@media (min-width: 1024px) {
  .layout {
    /* Desktop: Sidebar + main */
    grid-template-columns: 250px 1fr;
  }
}

Card grid:

Copy.cards {
  display: grid;
  gap: 1rem;
  
  /* Mobile: 1 column */
  grid-template-columns: 1fr;
}

@media (min-width: 640px) {
  .cards {
    /* Tablet: 2 columns */
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (min-width: 1024px) {
  .cards {
    /* Desktop: 3 columns */
    grid-template-columns: repeat(3, 1fr);
  }
}

@media (min-width: 1280px) {
  .cards {
    /* Large: 4 columns */
    grid-template-columns: repeat(4, 1fr);
  }
}

Hero section:

Copy.hero {
  padding: 2rem 1rem;
  text-align: center;
}

@media (min-width: 768px) {
  .hero {
    padding: 4rem 2rem;
  }
}

@media (min-width: 1024px) {
  .hero {
    padding: 6rem 3rem;
    text-align: left;
    display: grid;
    grid-template-columns: 1fr 1fr;
    align-items: center;
  }
}

Testing

Browser DevTools:

• Chrome: Device toolbar (Cmd+Shift+M)
• Firefox: Responsive Design Mode
• Safari: Enter Responsive Design Mode

Test on real devices:

• iPhone (various sizes)
• Android phones
• Tablets
• Different browsers

Responsive testing tools:

• BrowserStack
• LambdaTest
• Responsively App

Responsive Checklist

Layout:

• Mobile-first approach
• Flexible grid system
• No horizontal scrolling
• Content readable at all sizes

Typography:

• Readable font sizes (16px+ body)
• Appropriate line height
• Fluid typography for headings
• Proper text wrapping

Images:

• Responsive images
• Appropriate sizes for devices
• Fast loading
• Art direction where needed

Navigation:

• Mobile menu pattern
• Touch-friendly targets (44px+)
• Easy to use on mobile
• Accessible

Performance:

• Fast on mobile networks
• Optimized images
• Minimal layout shifts
• Touch interactions smooth

Best Practices

Use relative units:

Copy/* Good */
padding: 1rem;
font-size: 1.125rem;
width: 80%;

/* Avoid */
padding: 16px;
font-size: 18px;
width: 800px;

Test early and often:

• Test on mobile first
• Use real devices
• Test different orientations
• Test with slow connections

Progressive enhancement:

• Core functionality works on all devices
• Enhanced features for larger screens
• Graceful degradation

Copy