Mobile First Design

This walks you through the mobile-first methodology: start with a 320px baseline, nail the essential features and touch targets, then progressively enhance for tablets and desktops. You get breakpoint guidelines, performance optimization tips, and the core principle that constraints force better prioritization. The reference guides cover responsive patterns, mobile performance, and progressive enhancement strategies. Honest take: the approach is sound and the 44px touch target rule alone saves headaches, but the real value is in forcing you to justify every element before scaling up. Best for web apps and responsive sites where you need cross-device consistency without bloat.

skills.sh installs: 869
GitHub stars: 379
last updated: Aug 21, 2026

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Install

$ npx -y skills add aj-geddes/useful-ai-prompts --skill mobile-first-design --agent claude-code

Installs into .claude/skills of the current project.

Files

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

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## Responsive Breakpoints:

SKILL.md on GitHub