This skill creates production-grade frontend interfaces that are distinctive, accessible, and performant. Every project gets a bespoke aesthetic direction — no two designs should look alike.

The user provides: the client context (industry, audience, brand), the tech stack, and any design constraints.

Non-Negotiable Quality Standards

Every project MUST meet these. No exceptions, no shortcuts:

1. Mobile-First Responsive

• Design at 390px first, then scale up
• Test at 390px, 768px, 1280px+ breakpoints after implementing each component
• No horizontal scrolling at any breakpoint
• Touch targets ≥ 44×44px on mobile
• Stack layouts vertically on mobile, expand to grid on desktop

2. WCAG AA Accessibility

• Color contrast: 4.5:1 for normal text, 3:1 for large text (18px+ bold or 24px+)
• Keyboard navigation: every interactive element reachable via Tab, activatable via Enter/Space
• Focus indicators: visible focus ring on all interactive elements (never outline: none without replacement)
• ARIA: proper roles, labels, and descriptions. Headings in logical order (no skipped levels)
• Alt text: every <img> has meaningful alt text (or alt="" for decorative images)
• Form labels: every input has a visible <label>. Error messages linked via aria-describedby
• Screen readers: test with VoiceOver (macOS) — content must be logical when read linearly
• Reduced motion: respect prefers-reduced-motion — disable animations for users who opt out

3. Performance Budget

• No single component adds more than 50KB of JavaScript
• All images: use next/image with proper sizes and priority attributes
• Images served in modern formats (WebP/AVIF) via Next.js automatic optimization
• Total page JS bundle: flag if exceeding 200KB gzipped
• Animations: use LazyMotion + m from Framer Motion (tree-shakeable), never import motion directly
• Fonts: load via next/font with display: swap. Maximum 2 font families per project
• Lighthouse Performance score target: ≥ 90

4. Dark Mode Support

• Every project ships with working dark mode
• Use CSS variables in Tailwind v4 @theme for all colors
• Use dark: variants in Tailwind for component-level overrides
• Toggle mechanism: respect prefers-color-scheme system preference, with optional manual toggle
• Test both modes visually — dark mode is not an afterthought

/* Example: globals.css */
@import "tailwindcss";

@theme {
  --color-background: #f8f7f5;
  --color-foreground: #1c1917;
  --color-primary: #8e375c;
  --color-muted: #a8a29e;
}

@media (prefers-color-scheme: dark) {
  :root {
    --color-background: #1c1917;
    --color-foreground: #f5f5f4;
    --color-primary: #c76b94;
    --color-muted: #78716c;
  }
}

Aesthetic Direction — Decision Tree

Before writing any code, run this decision tree to select the right aesthetic for the client. Ask these questions (use AskUserQuestion or discuss with the user):

Q1: What is the client's industry?

Q2: Who is the primary audience?

Q3: What is the brand personality?

Result: Select one of these directions

1. Refined Professional

• Typography: Serif display (e.g., Playfair Display, DM Serif Display, Lora) + clean sans body (e.g., Inter, DM Sans, Source Sans 3)
• Palette: Muted, warm neutrals. One sophisticated accent (navy, burgundy, forest green). No bright colors.
• Layout: Symmetric, generous whitespace, max-w-5xl content, clear hierarchy
• Motion: Subtle — fade-in reveals on scroll, gentle hover states
• Spacing: py-20 md:py-28 section padding, relaxed line-height (1.7+)

2. Editorial Luxury

• Typography: Elegant serif (e.g., Cormorant Garamond, Libre Baskerville, Noto Serif Display) + refined sans (e.g., Outfit, Satoshi, General Sans)
• Palette: Near-monochrome with one rich accent. Black/cream base. Gold, plum, or deep teal accent.
• Layout: Magazine-inspired. Asymmetric grids, overlapping elements, dramatic hero images
• Motion: Moderate — parallax on heroes, staggered list reveals, text character animations
• Spacing: Very generous. Content floats in space. Negative space is a design element.

3. Clean Technical

• Typography: Modern geometric sans (e.g., Plus Jakarta Sans, Geist, Manrope) for both display and body
• Palette: Cool neutrals (slate, zinc). One vibrant accent (blue, violet, emerald). Clean whites.
• Layout: Grid-based, card-heavy, data-friendly. Dashboard-like precision.
• Motion: Functional — hover lifts on cards, smooth page transitions, loading states
• Spacing: Compact but not cramped. Efficient use of space. gap-6 between cards.

4. Warm Organic

• Typography: Rounded or humanist sans (e.g., Nunito, Quicksand, Rubik) or soft serif (e.g., Merriweather, Bitter)
• Palette: Earth tones — terracotta, sage, cream, warm brown. Soft pastels. No harsh contrasts.
• Layout: Rounded corners, soft shadows, flowing sections. Organic shapes (SVG blobs, curves).
• Motion: Gentle — slow fades, easing that feels natural, subtle breathing animations
• Spacing: Generous and flowing. Sections merge softly. Rounded containers.

5. Trustworthy Minimal

• Typography: Neutral, highly legible sans (e.g., IBM Plex Sans, Atkinson Hyperlegible, Open Sans) for everything
• Palette: High-contrast. Dark text on white. One institutional accent (blue, teal). No gradients.
• Layout: Simple, predictable, content-first. Single-column where possible. Large text.
• Motion: Minimal — content appears immediately. Maybe a single page-load fade.
• Spacing: Generous but functional. Focus on readability over aesthetics.

6. Bold Expressive

• Typography: Statement display fonts (e.g., Space Grotesk, Syne, Cabinet Grotesk, Clash Display) + contrasting body
• Palette: High saturation. Unexpected combinations. Dark backgrounds with neon accents. Or pure white with a single bold color.
• Layout: Breaking the grid. Oversized headings. Diagonal flow. Overlapping elements. Scroll-triggered reveals.
• Motion: Rich — page transitions, scroll-linked animations, hover transformations, parallax
• Spacing: Dramatic contrasts — tight in some areas, extremely open in others.

Font Selection Criteria

Since every project gets custom fonts, follow these rules:

1. Never reuse fonts across projects — each client gets a unique typographic identity
2. Always pair a display font with a body font — same font for both is lazy
3. Test at multiple sizes — display fonts must work at h1 AND h3 sizes
4. Check language support — verify the font covers all characters the client needs (accents, special chars)
5. Load via next/font — always. No external font CDN links.
6. Maximum 2 families — one display, one body. More than 2 hurts performance.
7. Avoid overused fonts — do NOT use: Inter (alone), Roboto, Open Sans, Montserrat, Poppins, Lato, or Raleway as display fonts. These are fine for body text paired with a distinctive display font.

Where to find distinctive fonts:

• Google Fonts (filter by popularity: avoid top 20)
• Fontsource (local hosting for any Google Font)
• Variable fonts preferred (one file, multiple weights)

Component Library: shadcn/ui

Always use shadcn/ui as the component base:

npx shadcn@latest add button input textarea label sheet

Customization approach:

• Override via CSS variables in globals.css (colors, radius, fonts)
• Override via Tailwind classes on the component (spacing, sizing)
• Never edit files in components/ui/ directly — customize via wrapper components if needed

Essential components to install per project:

• button, input, textarea, label — forms
• sheet — mobile navigation
• dialog — modals
• separator — visual dividers
• skeleton — loading states
• Add others as needed per project

Animation Tiers

Select the animation tier based on the aesthetic direction:

Tier 1: Subtle (Trustworthy Minimal, Refined Professional)

// Fade in on scroll, once
<m.div
  initial={{ opacity: 0, y: 16 }}
  whileInView={{ opacity: 1, y: 0 }}
  viewport={{ once: true }}
  transition={{ duration: 0.5 }}
/>

Tier 2: Moderate (Editorial Luxury, Warm Organic, Clean Technical)

// Staggered reveals + hover effects
<m.div
  initial={{ opacity: 0, y: 20 }}
  whileInView={{ opacity: 1, y: 0 }}
  viewport={{ once: true, margin: "-100px" }}
  transition={{ duration: 0.6, delay: index * 0.08 }}
/>

// Hover lift on cards
<m.div whileHover={{ y: -4, transition: { duration: 0.2 } }} />

Tier 3: Rich (Bold Expressive)

// Page transitions, parallax, character animations
// Use AnimatePresence for page transitions
// Use useScroll + useTransform for parallax
// Use staggerChildren for text reveals

Always respect prefers-reduced-motion:

const prefersReducedMotion = usePrefersReducedMotion();
const animation = prefersReducedMotion
  ? { opacity: 1, y: 0 }
  : { opacity: 0, y: 20 };

Implementation Workflow

For each component/page:

1. Select direction — run decision tree if not done yet
2. Choose fonts — pick a unique pairing, test at multiple sizes
3. Define palette — set CSS variables in globals.css, include dark mode
4. Build mobile-first — start at 390px, add responsive breakpoints going up
5. Add motion — select animation tier, implement with LazyMotion + m
6. Test accessibility — keyboard nav, contrast, screen reader, focus indicators
7. Screenshot at 390px + 1280px — verify responsive layout
8. Check dark mode — toggle and verify visually
9. Check performance — no unnecessary JS, images optimized

Anti-Patterns

• Cookie-cutter designs — if two client projects could swap stylesheets and look the same, you failed
• Desktop-first — designing at 1280px and "making it fit" on mobile always produces bad mobile UX
• Ignoring dark mode — adding it later is 5x harder. Build it from the start with CSS variables
• Animation overload — more animation ≠ better design. Match the tier to the aesthetic direction
• Generic font choices — Inter + no display font = looks like every other site built with AI
• Decorating instead of designing — gradients, shadows, and borders don't make a design good. Typography, spacing, and hierarchy do
• Skipping the decision tree — jumping to code without choosing a direction produces incoherent designs