What problem does it solve? Building responsive interfaces that work across phones, tablets, and desktops often leads to inconsistent breakpoints, unreadable text, and touch targets that fail accessibility standards. This Skill provides a complete set of mobile-first patterns for Tailwind CSS v4 so layouts scale correctly from 320px upward. ## Core Features & Use Cases - Breakpoint & Layout Systems: Content-driven breakpoint configuration, mobile-first grid and flexbox patterns, sidebar layouts, and holy-grail page structures. - Fluid Typography & Spacing: Clamp-based type and spacing scales that scale smoothly with the viewport while respecting user zoom preferences for WCAG compliance. - Touch & Accessibility Patterns: WCAG 2.2 compliant touch targets (44px minimum), safe-area handling for notched devices, and mobile navigation patterns including bottom nav bars. - Container Queries: Component-level responsiveness using @container so cards and widgets adapt to their parent rather than the viewport. - Use Case: When building a marketing page or dashboard, apply these patterns to get a responsive grid, fluid headings, compliant touch targets, and a mobile drawer navigation without writing custom media queries. ## Quick Start Use the tailwindcss-mobile-first skill to build a responsive landing page with fluid typography, a mobile hamburger menu, and WCAG-compliant touch targets.