This covers Apple's design foundations: color systems, typography, SF Symbols, accessibility, dark mode, materials, motion, and privacy guidelines. You'll want this when you're building iOS, macOS, or visionOS interfaces and need to check contrast ratios, implement Dynamic Type correctly, or figure out why your colors break in dark mode. It's organized around 17 reference documents covering everything from app icons to right-to-left layouts. The skill pushes you hard on accessibility from the start, which matches Apple's expectations but means you can't skip VoiceOver labels or Dynamic Type scaling. Works best when you're designing alongside Apple's platform conventions rather than fighting them.
npx skills add https://github.com/raintree-technology/apple-hig-skills --skill hig-foundations