axiom-design（公理设计）

Design & HIG

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

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)
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

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