Design

This covers Apple's modern design language with a focus on Liquid Glass effects and SwiftUI animations. You get practical implementation patterns for the glassEffect API on iOS 26+, plus AppKit's NSGlassEffectView for macOS. The animation side spans three generations of spring APIs, PhaseAnimator, KeyframeAnimator, and all the SF Symbol effects like bounce and wiggle. It's opinionated about performance, telling you to use GlassEffectContainer when you need multiple glass effects and to watch your GPU budget. The skill activates on anything from blur and transparency questions to matched geometry transitions. Really just reference material packaged as executable knowledge, which is exactly what you want when implementing visual effects without guessing at API names.