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mobile-first-design

aj-geddes/useful-ai-prompts · updated Apr 8, 2026

$npx skills add https://github.com/aj-geddes/useful-ai-prompts --skill mobile-first-design
summary

Mobile-first design prioritizes small screens as the starting point, ensuring core functionality works on all devices while leveraging larger screens for enhanced experience.

skill.md

Mobile-First Design

Table of Contents

Overview

Mobile-first design prioritizes small screens as the starting point, ensuring core functionality works on all devices while leveraging larger screens for enhanced experience.

When to Use

  • Web application design
  • Responsive website creation
  • Feature prioritization
  • Performance optimization
  • Progressive enhancement
  • Cross-device experience design

Quick Start

Minimal working example:

Mobile-First Approach:

Step 1: Design for Mobile (320px - 480px)
  - Constrained space forces priorities
  - Focus on essential content and actions
  - Single column layout
  - Touch-friendly interactive elements

Step 2: Enhance for Tablet (768px - 1024px)
  - Add secondary content
  - Multi-column layouts possible
  - Optimize spacing and readability
  - Take advantage of hover states

Step 3: Optimize for Desktop (1200px+)
  - Full-featured experience
  - Advanced layouts
  - Rich interactions
  - Multiple columns and sidebars

---
## Responsive Breakpoints:

Mobile: 320px - 480px
  - iPhone SE, older phones
// ... (see reference guides for full implementation)

Reference Guides

Detailed implementations in the references/ directory:

Guide Contents
Responsive Design Implementation Responsive Design Implementation
Mobile Performance Mobile Performance
Progressive Enhancement Progressive Enhancement

Best Practices

✅ DO

  • Design for smallest screen first
  • Test on real mobile devices
  • Use responsive images
  • Optimize for mobile performance
  • Make touch targets 44x44px minimum
  • Stack content vertically on mobile
  • Use hamburger menu on mobile
  • Hide non-essential content on mobile
  • Test with slow networks
  • Progressive enhancement approach

❌ DON'T

  • Assume all mobile users have fast networks
  • Use desktop-only patterns on mobile
  • Ignore touch interaction needs
  • Make buttons too small
  • Forget about landscape orientation
  • Over-complicate mobile layout
  • Ignore mobile performance
  • Assume no keyboard (iPad users)
  • Skip mobile user testing
  • Forget about notches and safe areas