Design & HIG

You MUST use this skill for ANY visual design, HIG compliance, Liquid Glass, SF Symbols, typography, or app composition work.

Not on Claude Code? Where this router says "Launch some-auditor agent", read that auditor's file in this suite and follow it inline — the same procedure, needing only file search and read.

Available here: skills/liquid-glass-auditor.md.

Agents that need Bash — builds, tests, simulators, crash symbolication — stay Claude Code-only; there is no inline equivalent for those.

Quick Reference

Decision Tree

digraph design {
    start [label="Design task" shape=ellipse];
    what [label="What do you need?" shape=diamond];

    start -> what;
    what -> "skills/hig.md" [label="design decision,\nHIG compliance,\ncolor/background choice"];
    what -> "skills/hig-ref.md" [label="semantic color API,\ncustom color code,\nmaterial style details"];
    what -> "skills/liquid-glass.md" [label="Liquid Glass effects,\nmigrate from blur,\nRegular vs Clear"];
    what -> "skills/liquid-glass-ref.md" [label="app-wide Liquid Glass plan,\nplatform differences,\nbackward compat"];
    what -> "skills/sf-symbols.md" [label="rendering mode choice,\nsymbol effects/animations,\ncustom symbols"];
    what -> "skills/sf-symbols-ref.md" [label="SF Symbols API syntax,\nUIKit equivalents,\navailability matrix"];
    what -> "skills/typography-ref.md" [label="font selection,\nDynamic Type,\ntext styles, tracking"];
    what -> "skills/app-composition.md" [label="@main entry point,\nauth flow, root view,\nscene lifecycle"];
}

1. Design decision / HIG compliance / choosing colors or backgrounds? → skills/hig.md 1a. Need semantic color API, custom color code, or material style details? → skills/hig-ref.md
2. Liquid Glass effects / migrating from blur / Regular vs Clear variant? → skills/liquid-glass.md 2a. Planning app-wide Liquid Glass adoption / platform differences / backward compatibility? → skills/liquid-glass-ref.md
3. SF Symbols rendering mode / symbol effects / custom symbols? → skills/sf-symbols.md 3a. Need SF Symbols API syntax / UIKit equivalents / availability check? → skills/sf-symbols-ref.md
4. Font selection / Dynamic Type / text styles / tracking / leading? → skills/typography-ref.md
5. App entry point / auth flow / root view switching / scene lifecycle? → skills/app-composition.md
6. SwiftUI view implementation? → /skill axiom-swiftui
7. TextKit / rich text editing / Writing Tools? → /skill axiom-uikit
8. Accessibility compliance (VoiceOver, contrast, touch targets)? → /skill axiom-accessibility
9. Audit UI for Liquid Glass adoption? → liquid-glass-auditor (Agent — surfaces migration opportunities AND adoption-completeness gaps: variant discipline, nesting hygiene, availability gating, primary-action tinting, accessibility re-check; scores ADOPTED / PARTIAL / NOT ADOPTED)
10. CarPlay app design, categories, driver-distraction rules? → /skill axiom-media (carplay-hig.md)

Platform-specific HIG

• watchOS design (glanceable UI, watchOS 10 navigation) → See axiom-watchos (skills/design-for-watchos.md)

Conflict Resolution

design vs swiftui: When building UI:

1. Use design FIRST — Decide what to build (colors, materials, typography, layout intent) before how to build it.
2. Then use swiftui — Implement the design decision in SwiftUI code.

design vs accessibility: When choosing colors or typography:

• Color contrast or Dynamic Type compliance? → use accessibility
• Which semantic color or text style to pick? → use design

design (liquid-glass) vs swiftui: When implementing Liquid Glass:

• What Liquid Glass is, when to use Regular vs Clear, migration strategy → use design (skills/liquid-glass.md)
• SwiftUI code for .glassEffect() modifier → use design (skills/liquid-glass-ref.md), then swiftui for surrounding view code

design (app-composition) vs swiftui: When structuring app architecture:

• @main entry, auth state machine, root view switching, scene lifecycle → use design (skills/app-composition.md)
• NavigationStack, NavigationSplitView, tab structure → use swiftui

design vs media (CarPlay): When designing for CarPlay:

• General iOS HIG principles (colors, typography, Liquid Glass) → use design
• CarPlay-specific rules (app categories, entitlement review, template-only UI, driver distraction, per-category design rules) → invoke axiom-media (skills/carplay-hig.md)
• CarPlay rules are stricter than iOS HIG and enforced at entitlement review, not just App Store review.

Critical Patterns

HIG Quick Decisions (skills/hig.md):

• Background color decision tree (media-focused vs standard)
• Typography selection (headline vs body vs caption)
• Color usage guidelines and when to use semantic vs custom colors
• Design review checklist for HIG compliance

HIG Comprehensive Reference (skills/hig-ref.md):

• All semantic colors with platform availability
• Custom color patterns with dark mode support
• Background hierarchy and material styles
• Code examples for every color and background pattern

Liquid Glass (skills/liquid-glass.md):

• What Liquid Glass is and how it differs from blur effects
• Regular vs Clear variant selection
• Migration strategy from pre-iOS 26 materials
• Tinting, legibility, and adaptive behavior troubleshooting
• Expert review criteria for Liquid Glass implementations

Liquid Glass Adoption (skills/liquid-glass-ref.md):

• App-wide adoption planning (icons, controls, navigation, menus)
• Platform-specific behavior (iOS, iPadOS, macOS, tvOS, watchOS)
• Backward compatibility strategy for supporting pre-Liquid Glass
• Accessibility compliance with Liquid Glass interfaces

SF Symbols (skills/sf-symbols.md):

• Rendering mode selection (Monochrome, Hierarchical, Palette, Multicolor)
• Symbol effect selection (Bounce, Pulse, Scale, Wiggle, Rotate, Breathe, Draw)
• Custom symbol creation workflow
• Troubleshooting effects not playing, weight mismatches

SF Symbols API (skills/sf-symbols-ref.md):

• Exact API signatures for rendering modes and effects
• UIKit/AppKit equivalents for every SwiftUI symbol API
• Platform availability matrix
• Configuration options (weight, scale, variable values)

Typography (skills/typography-ref.md):

• San Francisco font system (Pro, Compact, Mono, New York)
• Text styles with Dynamic Type scaling
• Tracking and leading values
• Internationalization considerations

App Composition (skills/app-composition.md):

• @main entry point and root view patterns
• Authentication state machine (login, onboarding, main)
• Flicker-free root view switching
• scenePhase lifecycle handling and state restoration
• Document-based apps: the OS27 @Observable document model (ReadableDocument/WritableDocument) + DocumentGroup

Anti-Rationalization

Example Invocations

User: "Should I use a dark or light background?" -> Read: skills/hig.md

User: "What semantic color should I use for secondary text?" -> Read: skills/hig-ref.md

User: "How do I implement Liquid Glass in my app?" -> Read: skills/liquid-glass.md

User: "I need to plan Liquid Glass adoption across my whole app" -> Read: skills/liquid-glass-ref.md

User: "My SF Symbol is flat, I want it to have depth" -> Read: skills/sf-symbols.md

User: "What's the SwiftUI API for symbol effects?" -> Read: skills/sf-symbols-ref.md

User: "Which font should I use for body text?" -> Read: skills/typography-ref.md

User: "How do I switch between login and main screens?" -> Read: skills/app-composition.md

User: "Check my app's UI for HIG compliance" -> Read: skills/hig.md, then /skill axiom-accessibility for contrast/Dynamic Type

User: "I want my download button icon to animate" -> Read: skills/sf-symbols.md