A solid reference for modern CSS layout patterns that'll save you from reinventing responsive breakpoints every time. Covers the essentials: mobile-first media queries at 640px and 1024px, CSS Grid for multi-column layouts, Flexbox for navigation, and fluid typography using clamp(). The examples are clean and copy-paste ready, which is honestly what you want when you're spinning up a new layout. Best practices section nails the basics like 48px touch targets and readable line lengths. Nothing groundbreaking here, but it's well-organized and hits the patterns you actually use in production. Good for quick consultation or sharing with junior developers who need to understand the mobile-first approach.
npx skills add https://github.com/secondsky/claude-skills --skill responsive-web-design