Responsive Design

This skill covers responsive design principles — mobile-first development, appropriate breakpoints, touch-friendly targets, and adaptive layout patterns.

Use-When

This skill activates when:

• Agent builds page layouts or components
• Agent adds responsive breakpoints
• Agent designs for mobile devices
• Agent creates touch-friendly interactions
• Agent converts desktop-only designs to responsive

Core Rules

• ALWAYS use mobile-first approach (base styles for mobile, media queries for larger)
• ALWAYS ensure touch targets are at least 44x44px
• ALWAYS design for smallest screen first, then enhance
• NEVER rely solely on device detection (use feature detection)
• ALWAYS test at actual breakpoints, not just resize the browser

Common Agent Mistakes

• Desktop-first approach leading to mobile afterthought
• Touch targets too small (buttons, links under 44px)
• Fixed widths that break on smaller screens
• Not considering landscape orientation on mobile
• Hiding content instead of adapting it

Examples

✅ Correct

// Mobile-first: base styles for mobile, enhance for larger
<div className="w-full md:w-1/2 lg:w-1/3">
  <Button className="w-full md:w-auto h-11">
    Submit
  </Button>
</div>

// Touch-friendly targets (min 44px)
<button className="min-h-[44px] min-w-[44px] px-4 py-3">
  Tap Here
</button>

❌ Wrong

// Desktop-first
<div className="w-1/2">
  <button className="p-1">Click</button>
</div>

// Touch target too small
<button className="p-2 text-sm">
  Too small
</button>

References

• MDN Responsive Design
• Google Mobile-Friendly
• Apple Human Interface Guidelines – Layout