Responsive Design Check Skill

Mobile-first responsive design verification for Tailwind CSS projects.

When to Activate

• User mentions "반응형", "모바일", "responsive", "mobile", "breakpoint"
• Reviewing layout components
• Testing across screen sizes

Breakpoint Reference

Name	Tailwind	Range	Characteristics
Mobile	default	<640px	Single column, touch UI
Small	sm:	≥640px	Extended mobile
Medium	md:	≥768px	Tablet, 2-column possible
Large	lg:	≥1024px	Desktop, sidebar
XL	xl:	≥1280px	Wide desktop
2XL	2xl:	≥1536px	Large monitors

Checklist

1. Layout

Container

• Max-width constraints (max-w-6xl, max-w-7xl)
• Center alignment (mx-auto)
• Responsive padding (px-4 md:px-6 lg:px-8)

Grid/Flex

• Mobile: single column
• Tablet: 2-column (md:grid-cols-2)
• Desktop: multi-column (lg:grid-cols-3)
• flex-col md:flex-row pattern

Navigation

• Mobile: hamburger menu or bottom nav
• Desktop: sidebar or top nav
• hidden md:flex / md:hidden pattern

2. Typography

Responsive Font Sizes

• Headings: text-xl md:text-2xl lg:text-3xl
• Body: default 16px (no change needed)
• Small text: text-xs sm:text-sm

Text Visibility

• Long text truncated on mobile
• truncate or line-clamp-* usage
• hidden sm:inline pattern

3. Interactive Elements

Touch Targets

• Minimum 44x44px (buttons, links)
• Sufficient spacing (8px+)
• Keep p-2 not p-2 md:p-1

Hover vs Touch

• Consider @media (hover: hover)
• Touch alternatives for hover effects
• Clear click/tap feedback

4. Images/Media

Responsive Images

• w-full or max-w-full
• Proper object-cover / object-contain
• srcset or Next.js Image component

Aspect Ratio

• Use aspect-video, aspect-square
• Avoid fixed heights (h-[300px])

5. Show/Hide Patterns

// ✅ Correct
<div className="hidden md:block">Desktop only</div>
<div className="md:hidden">Mobile only</div>

// ❌ Incorrect (JS-dependent)
<div style={{display: isMobile ? 'block' : 'none'}}>
  // SEO/accessibility issues
</div>

Report Format

# 📱 Responsive Design Report

## Summary
- **Mobile**: ✅/⚠️/❌
- **Tablet**: ✅/⚠️/❌
- **Desktop**: ✅/⚠️/❌

## Issues by Breakpoint

### Mobile (<768px)
- [Issue] description

### Tablet (768-1024px)
- [Issue] description

### Desktop (>1024px)
- [Issue] description

## Recommendations
[Improvement suggestions]

Project-Specific Patterns

This project uses:

• Sidebar: hidden md:flex (hidden on mobile)
• MobileNav: md:hidden (hidden on desktop)
• Container: max-w-6xl mx-auto w-full px-6
• Sidebar collapse: icons only on tablet