This skill encodes design principles derived from comparing polished, production-quality SwiftUI apps against poorly-built ones. The patterns here represent what separates an app that feels "right" from one where the margins, spacing, and text sizes just look "off." Apply these principles whenever building or modifying SwiftUI interfaces, WidgetKit widgets, or any native Apple UI. Core Philosophy Restraint over decoration. Every pixel must earn its place. A polished app uses fewer colors, fewer font sizes, fewer spacing values, and fewer words — but uses them consistently. Over-engineering vi…