material-design-3（材料设计 3）

Material Design 3 (Material You) Skill

🎯 Purpose

This skill provides comprehensive guidance on Material Design 3 (also known as Material You), Google's latest design system that emphasizes personalization, accessibility, and modern UI patterns for Angular applications.

📦 What is Material Design 3?

Material Design 3 is Google's latest design language that introduces:

• Dynamic Color: Adaptive color palettes based on user preferences
• Enhanced Accessibility: WCAG 2.1 AA compliance by default
• Flexible Theming: Token-based theming system
• Modern Components: Updated component designs with better customization
• Personalization: User-centric design that adapts to preferences

🎨 When to Use This Skill

Use Material Design 3 guidance when:

• Implementing a new Angular application with Material Design
• Migrating from Material Design 2 to Material Design 3
• Creating custom themes using Material Design 3 tokens
• Implementing dynamic color theming
• Building accessible, modern UI components
• Following Material You design principles
• Working with Material Design 3 typography and spacing systems

🛠️ Core Concepts

1. Color System

Material Design 3 introduces a sophisticated color system:

Color Roles:

• Primary: Main brand color for prominent actions
• Secondary: Supporting color for less prominent actions
• Tertiary: Accent color for highlights and contrasts
• Error: Color for error states
• Surface: Background colors for components
• On-colors: Contrasting text/icon colors (on-primary, on-secondary, etc.)

Color Variants:

• Container colors (e.g., primary-container)
• On-container colors (e.g., on-primary-container)
• Surface variants (surface-dim, surface-bright, surface-container)

2. Dynamic Color

Material Design 3's signature feature:

• Generate color schemes from source colors
• Support both light and dark themes
• Automatic contrast adjustments
• System-level color extraction (from wallpaper on supported platforms)

3. Typography

Five typography scales:

• Display: Largest text (display-large, display-medium, display-small)
• Headline: Section headers (headline-large to headline-small)
• Title: Subsection titles (title-large to title-small)
• Body: Main content (body-large, body-medium, body-small)
• Label: UI labels (label-large to label-small)

4. Elevation

Three elevation strategies:

• Shadow: Traditional elevation with shadows
• Overlay: Tonal surface overlays
• Combined: Shadow + overlay for enhanced depth perception

5. Shape

Rounded corner system with four scales:

• None: 0dp (sharp corners)
• Extra Small: 4dp
• Small: 8dp
• Medium: 12dp
• Large: 16dp
• Extra Large: 28dp

📚 Implementation in Angular

Setting Up Material Design 3 Theme

// Define your theme using M3 tokens
@use '@angular/material' as mat;

// Include core Material Design 3 styles
@include mat.core();

// Define your color palette
$my-primary: mat.define-palette(mat.$azure-palette);
$my-accent: mat.define-palette(mat.$blue-palette);
$my-warn: mat.define-palette(mat.$red-palette);

// Create the theme
$my-theme: mat.define-theme((
  color: (
    theme-type: light,
    primary: $my-primary,
    tertiary: $my-accent,
  ),
  typography: (
    brand-family: 'Roboto',
    bold-weight: 700
  ),
  density: (
    scale: 0
  )
));

// Apply the theme
@include mat.all-component-themes($my-theme);

// Dark theme variant
$my-dark-theme: mat.define-theme((
  color: (
    theme-type: dark,
    primary: $my-primary,
    tertiary: $my-accent,
  )
));

// Apply dark theme when needed
.dark-theme {
  @include mat.all-component-colors($my-dark-theme);
}

Using Color Tokens

// Access theme colors in your components
.my-component {
  background-color: var(--mat-sys-primary);
  color: var(--mat-sys-on-primary);

  &:hover {
    background-color: var(--mat-sys-primary-container);
    color: var(--mat-sys-on-primary-container);
  }
}

// Surface variants
.surface {
  background-color: var(--mat-sys-surface);
  color: var(--mat-sys-on-surface);
}

.surface-container {
  background-color: var(--mat-sys-surface-container);
}

Typography Usage

// Using typography tokens
.heading {
  font: var(--mat-sys-headline-large);
}

.body-text {
  font: var(--mat-sys-body-medium);
}

.label {
  font: var(--mat-sys-label-small);
}

Elevation and Shadows

.elevated-card {
  // Level 1 elevation
  box-shadow: var(--mat-sys-level1);

  &:hover {
    // Level 2 elevation on hover
    box-shadow: var(--mat-sys-level2);
  }
}

🎯 Best Practices

1. Theme Consistency

• Use design tokens instead of hardcoded values
• Maintain consistent color usage across components
• Follow Material Design 3 color role guidelines

2. Accessibility

• Ensure minimum 4.5:1 contrast ratio for text
• Use semantic color roles (primary, secondary, error)
• Support both light and dark themes
• Provide sufficient touch target sizes (48x48dp minimum)

3. Responsive Design

• Use Material Design 3 breakpoints
• Adapt layouts for different screen sizes
• Test on mobile, tablet, and desktop viewports

4. Dynamic Theming

// Example: Dynamic theme switching in Angular
export class ThemeService {
  private isDark = signal(false);

  toggleTheme() {
    this.isDark.update(dark => !dark);
    document.body.classList.toggle('dark-theme', this.isDark());
  }

  applyCustomColors(sourceColor: string) {
    // Generate M3 palette from source color
    const palette = this.generateM3Palette(sourceColor);
    this.applyCSSVariables(palette);
  }
}

🔧 Common Patterns

Custom Component with M3 Tokens

@Component({
  selector: 'app-custom-button',
  template: `
    <button class="m3-button" [class.filled]="variant === 'filled'">
      <ng-content></ng-content>
    </button>
  `,
  styles: [`
    .m3-button {
      padding: 10px 24px;
      border-radius: var(--mat-sys-corner-full);
      font: var(--mat-sys-label-large);
      border: none;
      cursor: pointer;

      &.filled {
        background-color: var(--mat-sys-primary);
        color: var(--mat-sys-on-primary);

        &:hover {
          background-color: var(--mat-sys-primary-container);
          color: var(--mat-sys-on-primary-container);
        }
      }

      &.outlined {
        background-color: transparent;
        border: 1px solid var(--mat-sys-outline);
        color: var(--mat-sys-primary);
      }
    }
  `]
})
export class CustomButtonComponent {
  @Input() variant: 'filled' | 'outlined' = 'filled';
}

🐛 Troubleshooting

📖 References

• Material Design 3 Official Guidelines
• Angular Material Theming Guide
• Material Design Color System
• Material Design Typography
• Accessibility Guidelines

💡 Migration from Material Design 2

Key changes when migrating from M2 to M3:

1. Replace color palette with theme-type approach
2. Update component styles to use design tokens
3. Migrate custom themes to new theming API
4. Update typography from mat-typography-level to M3 tokens
5. Replace elevation mixins with CSS custom properties
6. Test accessibility with new contrast requirements

📂 Recommended Placement

Project-level skill:

/.github/skills/material-design-3/skill.md

Personal global skill:

~/.github/skills/material-design-3/skill.md

Copilot will automatically load this skill when Material Design 3 topics are mentioned.