Design engineering principles for making SwiftUI interfaces feel polished on Apple platforms. Use when building or reviewing SwiftUI views, implementing animations, transitions, springs, micro-interactions, haptics, SF Symbol effects, press states, enter/exit animations, or any visual detail work in Swift. Triggers on UI polish, "make it feel better", "feels off", "make this view nicer", stagger/spring animations, corner radius, optical alignment, monospaced/numeric text, Dynamic Type, Reduce Motion, scale on press, sensoryFeedback, separators, shadows, materials, and iOS 26 Liquid Glass. SwiftUI only (iOS/iPadOS-focused).
