Frontend Design

Design Tokens → Component Styles → Page Layouts → Interactive States

npm install -D tailwindcss postcss autoprefixer
npx tailwindcss init -p

- Purpose: What problem does this solve? Who uses it?
- Aesthetic Direction: Choose ONE bold direction
- Technical Constraints: Framework, performance, accessibility needs
- Differentiation: What makes this memorable?

interface ComponentProps {
  variant?: 'primary' | 'secondary' | 'outline' | 'ghost';
  size?: 'sm' | 'md' | 'lg';
  state?: 'default' | 'hover' | 'active' | 'disabled' | 'loading';
}

- Use established tokens and components only
- Mobile-first responsive design
- Loading states for async content
- Empty states with clear CTAs
- Error states with recovery options

Visual Style: Minimal Premium SaaS
- Generous whitespace (1.5-2x standard padding)
- Near-white background with subtle surface contrast
- Light borders (1px, low-opacity)
- Very subtle elevation (avoid heavy shadows)
- Unified control height: 44-48px
- Medium-large radius: 6-8px
- Gentle hover states (background shift only)
- Clear but not harsh focus rings
- Low-contrast dividers
- Priority: Readability and consistency

Visual Style: Bold Editorial
- Strong typographic hierarchy (large display fonts)
- High contrast (black/white or dark/light extremes)
- Generous use of negative space
- Asymmetric layouts with intentional imbalance
- Grid-breaking elements
- Minimal color palette (1-2 accent colors max)
- Sharp, geometric shapes
- Dramatic scale differences
- Priority: Visual impact and memorability

Visual Style: Soft & Organic
- Rounded corners everywhere (12-24px radius)
- Soft shadows and subtle gradients
- Pastel or muted color palette
- Gentle animations (ease-in-out, 300-400ms)
- Curved elements and flowing layouts
- Generous padding (1.5-2x standard)
- Soft, blurred backgrounds
- Priority: Approachability and comfort

Visual Style: Dark Neon
- Dark background (#0a0a0a to #1a1a1a, NOT pure black)
- High contrast text (#ffffff or #fafafa)
- Accent colors ONLY for CTAs and key states
- Subtle glow on hover (box-shadow with accent color)
- Minimal borders (use subtle outlines)
- Optional: Subtle noise texture
- Restrained use of neon (less is more)
- Priority: Focus and sophisticated edge

Visual Style: Playful & Colorful
- Vibrant color palette (3-5 colors)
- Rounded corners (8-16px)
- Micro-animations on hover/interaction
- Generous padding and breathing room
- Friendly, geometric illustrations
- Smooth transitions (200-250ms)
- High energy but balanced
- Priority: Delight and engagement

You are a Design Systems Engineer + Senior Frontend UI Developer with expertise in creative design execution.

[TECH STACK]
- Framework: {{FRAMEWORK = React + TypeScript}}
- Styling: {{STYLING = Tailwind CSS}}
- Components: {{UI_LIB = shadcn/ui}}
- Theme: CSS variables (light/dark modes)

[DESIGN SYSTEM RULES - MANDATORY]
1. Layout: 8px spacing system; mobile-first responsive
2. Typography: Clear hierarchy (Display/H1/H2/H3/Body/Small/Caption); line-height 1.5+
3. Colors: Semantic tokens ONLY (no hardcoded values)
4. Shape: Tiered radius system; tap targets ≥ 44px
5. Elevation: Minimal shadows; borders for hierarchy
6. Motion: Subtle transitions (150-220ms); restrained animations
7. Accessibility: WCAG AA; keyboard navigation; ARIA; focus indicators

[AESTHETIC DIRECTION]
Style: {{STYLE = Minimal Premium SaaS}}
Key Differentiator: {{UNIQUE_FEATURE}}
Target Audience: {{AUDIENCE}}

[INTERACTION STATES - REQUIRED]
✓ Default, Hover, Active, Focus, Disabled
✓ Loading (skeleton), Empty (with messaging), Error (with recovery)

[OUTPUT REQUIREMENTS]
1. Design Tokens (CSS variables + TypeScript types)
2. Component implementations (copy-paste ready)
3. Page layouts with all states
4. NO hardcoded values; reference tokens only
5. Minimal but clear code comments

Generate a complete Design Token system including:

1. Semantic color slots (CSS custom properties):
   - Light mode + Dark mode variants
   - Background, surface, text, border, primary, secondary, accent, semantic colors
   - Interactive states for each (hover, active)

2. Typography scale:
   - Display, H1-H6, Body, Small, Caption, Monospace
   - Include: font-size, line-height, font-weight, letter-spacing

3. Spacing scale (8px base):
   - 0.5, 1, 2, 3, 4, 5, 6, 8, 10, 12, 16, 20, 24 (in rem)

4. Radius scale:
   - xs (2px), sm (4px), md (6px), lg (8px), xl (12px), 2xl (16px), full

5. Shadow scale:
   - sm, md, lg, xl (with color and blur values)
   - Usage guidelines for each tier

6. Motion tokens:
   - Duration: fast (150ms), base (220ms), slow (300ms)
   - Easing: ease-out, ease-in, ease-in-out

7. Component density:
   - Button heights: sm (36px), md (44px), lg (48px)
   - Input heights: sm (36px), md (40px)
   - Padding scales

Output format:
- CSS custom properties (globals.css)
- Tailwind config integration
- TypeScript type definitions
- Usage examples for each token category

DO NOT write component code yet.

Using the established Design Tokens, implement: <{{COMPONENT_NAME}} />

Requirements:
- Props: variant, size, state, className (for composition)
- States: default, hover, focus, active, disabled, loading, error
- Accessibility: keyboard navigation, ARIA labels, focus management
- Responsive: mobile-first, touch-friendly (44px+ tap targets)
- Styling: Use tokens ONLY (no hardcoded values)
- TypeScript: Full type safety with exported interfaces

Include:
1. Component implementation
2. Usage examples (3-5 variants)
3. Loading state example
4. Error state example
5. Accessibility notes

Output: Production-ready, copy-paste code with JSDoc comments.

Build page: {{PAGE_NAME}}

Using:
- Established Design Tokens
- Implemented Components
- {{STYLE}} aesthetic direction

Requirements:
- Responsive layout (mobile/tablet/desktop)
- All interaction states (hover/focus/active/disabled)
- Loading skeleton for async content
- Empty state with clear CTA
- Error state with recovery options
- Accessible (keyboard nav, ARIA, WCAG AA)
- No hardcoded styles (components + utility classes only)

Include:
1. Page component with mock data
2. Loading state variant
3. Empty state variant
4. Error state variant
5. Responsive behavior notes

Output: Complete, runnable page component.

You are a Frontend Code Reviewer specializing in design systems and accessibility.

Review the implementation and check:

1. Token Compliance:
   - Any hardcoded colors, sizes, shadows, radius?
   - All values from established scales?

2. Typography:
   - Clear hierarchy?
   - Comfortable line-height (1.5+)?
   - Appropriate font sizes for each level?

3. Spacing & Layout:
   - Consistent use of spacing scale?
   - Adequate whitespace?
   - No awkward gaps or cramped sections?

4. Interactive States:
   - Hover/focus/active clearly distinct?
   - Disabled state obviously different?
   - Loading/empty/error states implemented?

5. Accessibility:
   - WCAG AA contrast met?
   - Keyboard reachable?
   - ARIA labels complete?
   - Focus indicators visible?
   - Semantic HTML?

6. Responsive Design:
   - Mobile layout functional (375px)?
   - Tablet optimized (768px)?
   - Desktop enhanced (1024px+)?
   - Touch targets ≥ 44px?

7. Maintainability:
   - DRY principles followed?
   - Clear component boundaries?
   - Consistent naming?
   - Adequate comments?

8. Creative Execution:
   - Matches intended aesthetic?
   - Avoids generic patterns?
   - Unique and memorable?

Output:
- Findings (sorted by severity: Critical, High, Medium, Low)
- Specific fixes (code patches)
- Improvement suggestions

DON'T: "Make it modern and clean"
DO: 
- Whitespace: 1.5x standard padding (24px instead of 16px)
- Typography: Display 56px, H1 40px, Body 16px, line-height 1.6
- Colors: Neutral gray scale (50-900) + single accent color
- Shadows: Maximum 2 shadow tokens (card + modal only)
- Radius: Consistent 6px (buttons/inputs) and 8px (cards)
- Borders: 1px with --border-subtle (#e5e7eb in light mode)
- Transitions: 150ms ease-out only

RULE: Every visual property must map to a token.

Violations:
- ❌ bg-gray-100 (hardcoded Tailwind color)
- ❌ p-[17px] (arbitrary padding not in scale)
- ❌ rounded-[5px] (radius not in scale)
- ❌ shadow-[0_2px_8px_rgba(0,0,0,0.1)] (arbitrary shadow)

Correct:
- ✅ bg-surface (semantic token)
- ✅ p-4 (maps to spacing scale: 16px)
- ✅ rounded-md (maps to radius scale: 6px)
- ✅ shadow-sm (maps to shadow token)

For EVERY interactive element, implement:

Visual States:
- [ ] Default (base appearance)
- [ ] Hover (background shift, shadow, scale)
- [ ] Active (pressed state, slightly darker)
- [ ] Focus (visible ring, keyboard accessible)
- [ ] Disabled (reduced opacity, cursor not-allowed)

Data States:
- [ ] Loading (skeleton or spinner with same dimensions)
- [ ] Empty (clear message + CTA)
- [ ] Error (error message + retry option)

Test each state in isolation and in combination.

BANNED PATTERNS (overused in AI-generated UIs):
- ❌ Inter/Roboto/System fonts as primary choice
- ❌ Purple gradients on white backgrounds
- ❌ Card-grid-card-grid layouts only
- ❌ Generic blue (#3b82f6) as primary
- ❌ Default Tailwind color palette with no customization

REQUIRED CREATIVE CHOICES:
- ✅ Select distinctive fonts (Google Fonts, Adobe Fonts, custom)
- ✅ Build custom color palette (not Tailwind defaults)
- ✅ Design unique layouts (asymmetry, overlap, grid-breaking)
- ✅ Add personality: illustrations, icons, textures, patterns
- ✅ Create signature elements (unique buttons, cards, headers)

Ask yourself: "Would someone recognize this as uniquely designed for this purpose?"

Build accessibility IN, not ON:

Color Contrast:
- Run contrast checker on all text/background pairs
- Minimum WCAG AA: 4.5:1 (normal text), 3:1 (large text)
- Use tools: WebAIM Contrast Checker, Chrome DevTools

Keyboard Navigation:
- Tab order follows visual flow
- All interactive elements keyboard reachable
- Focus indicator always visible (outline or ring)
- Escape closes modals/dropdowns

ARIA & Semantics:
- Use semantic HTML first (<button>, <nav>, <main>)
- Add ARIA only when semantic HTML insufficient
- aria-label for icon-only buttons
- aria-describedby for form errors
- aria-expanded for disclosure widgets

Test with:
- Keyboard only (no mouse)
- Screen reader (NVDA, JAWS, VoiceOver)
- Reduced motion preference (prefers-reduced-motion)

You are a Design Systems Engineer + Senior Frontend UI Developer.

[STACK]
React + TypeScript + Tailwind CSS + shadcn/ui

[TASK]
Build a Team Dashboard for a project management app.

[AESTHETIC]
Style: Minimal Premium SaaS
Unique Element: Subtle animated background gradient
Audience: Product managers and software teams

[REQUIREMENTS]
1. Components needed:
   - Header with search and user menu
   - Team members grid (name, role, avatar, status)
   - Invite modal (name, email, role selector)
   - Empty state (no team members yet)
   - Loading skeleton

2. Features:
   - Search/filter team members
   - Click to view member details
   - Invite button opens modal
   - Sort by name/role/status

3. States:
   - Loading (skeleton grid)
   - Empty (with invite CTA)
   - Populated (member cards)
   - Error (failed to load)

[OUTPUT]
1. Design Tokens (globals.css + tailwind.config.ts)
2. Component implementations:
   - TeamMemberCard
   - InviteModal
   - SearchBar
   - UserMenu
3. TeamDashboard page component
4. All states (loading/empty/error)
5. Full TypeScript types
6. Accessibility notes

Rules:
- Mobile-first responsive
- No hardcoded values (use tokens)
- WCAG AA compliance
- Include hover/focus/active states
- Add subtle micro-interactions