Frontend Design Skill

This skill guides creation of distinctive, production-grade frontend interfaces. It automatically detects the project's existing design system and frontend framework, respects them first, then channels creativity through composition, layout, and motion.

The user provides frontend requirements: a component, page, application, or interface to build. They may include context about the purpose, audience, or technical constraints.

Step 1: Codebase Context Discovery (MANDATORY)

Before writing any code or choosing any aesthetic direction, scan the codebase. This step is non-negotiable and runs every time.

What to Detect

1. Frontend framework — Check package.json (or equivalent) for: react, vue, angular, svelte, next, nuxt, astro, solid-js
2. Component library — Check dependencies for: PrimeVue, shadcn/ui, Vuetify, MUI, Chakra UI, Ant Design, Radix, Mantine, Quasar, Element Plus, Headless UI
3. CSS framework / methodology — Check for:
   • Tailwind: tailwind.config.* files or @tailwind directives
   • CSS Modules: *.module.css files
   • Styled-components / Emotion: imports in component files
   • SCSS/SASS: *.scss files, variable files
   • CSS-in-JS: check imports
4. Design tokens — Scan for:
   • CSS custom properties files (variables.css, tokens.css, :root blocks)
   • Tailwind theme extensions in tailwind.config.*
   • SCSS variable files (_variables.scss, _tokens.scss)
   • Theme configuration files
5. Existing typography — Check for font declarations in:
   • Entry points (index.html, _app.tsx, layout.tsx, nuxt.config.*, app.vue)
   • Global CSS files
   • Font import statements (Google Fonts, local fonts)
6. Existing color palette — Look for defined colors in theme files, CSS variables, Tailwind config
7. Component patterns — Examine 2-3 existing components to understand:
   • Naming conventions (PascalCase, kebab-case)
   • Directory structure
   • Styling approach used in practice
8. Design system rules — Check for design system rules in CLAUDE.md, .cursor/rules, or other agent configuration files (the create-design-system-rules skill generates these)

Context Summary

After scanning, internally classify the project into one of three tiers:

Tier	Condition	Behavior
Tier 1: Greenfield	No framework, no component library, no design tokens (standalone HTML, one-off artifact, new project)	Full creative freedom — proceed to Step 2 Path B
Tier 2: Framework present	Framework and/or CSS framework detected, but no established design system or component library	Use framework idioms, express creativity through theming, layout, and composition
Tier 3: Design system present	Component library + design tokens + established patterns detected	Strict adherence to existing system; creativity through composition, motion, and micro-interactions only

State your findings before proceeding. Example: "Detected: Vue 3 + PrimeVue + Tailwind CSS with custom theme. Tier 3 — I will use PrimeVue components and existing design tokens."

Step 2: Design Thinking

Path A: Design Within an Existing System (Tier 2 & 3)

When an existing design system or framework is detected, creative expression is channeled — not suppressed.

Hard constraints (NEVER violate):

• NEVER import fonts that are not already in the project's font stack
• NEVER override existing design tokens (CSS variables, Tailwind theme values, SCSS variables)
• NEVER create components that duplicate existing library components (if the library has a Button, use it)
• NEVER introduce a CSS methodology that differs from the project's approach (if the project uses Tailwind, use Tailwind — not inline styles or CSS Modules)
• NEVER add external CDN links for styling resources not already used

Creative layer (WHERE distinctiveness lives):

• Spatial composition — Unexpected layouts using the existing grid system: asymmetric arrangements, dramatic whitespace, overlapping sections, diagonal flow, grid-breaking hero areas
• Motion and animation — Staggered reveals, scroll-triggered transitions, hover state choreography, page load orchestration. Use the project's animation approach (CSS transitions, Motion library, GSAP — whatever is already installed or appropriate for the framework)
• Content hierarchy — Dramatic size contrasts within the existing type scale, bold use of font weight variations, creative letter-spacing, text-transform as a design tool
• Color accent strategy — Within the existing palette, use dominant/accent relationships intentionally. A design system defines colors; this skill decides how to deploy them for maximum impact
• Component composition — Combine existing primitives in unexpected ways: a DataTable with editorial-quality header treatment, a Card grid with magazine-style layout, a Form with conversational flow
• Micro-interactions — Purposeful feedback on every interactive element: button press effects, input focus animations, loading state choreography, success/error transitions
• Whitespace as design — Generous padding, breathing room between sections, whitespace that creates visual rhythm

Think like a designer at a company with an established brand: you don't replace the brand typeface — you create distinction through how you compose the existing elements.

Path B: Design From Scratch (Tier 1 — Greenfield)

When no existing system is detected, commit to a BOLD aesthetic direction:

• Purpose: What problem does this interface solve? Who uses it?

• Tone: Pick a clear aesthetic direction:

  • Brutally minimal
  • Maximalist chaos
  • Retro-futuristic
  • Organic/natural
  • Luxury/refined
  • Playful/toy-like
  • Editorial/magazine
  • Brutalist/raw
  • Art deco/geometric
  • Soft/pastel
  • Industrial/utilitarian

  Use these for inspiration but design one that is true to the aesthetic direction.

• Differentiation: What makes this UNFORGETTABLE? What's the one thing someone will remember?

CRITICAL: Choose a clear conceptual direction and execute it with precision. Bold maximalism and refined minimalism both work — the key is intentionality, not intensity.

Implementation Standards

For All Tiers

Implement working code that is:

• Production-grade and functional
• Cohesive with a clear visual point-of-view
• Meticulously refined in every detail
• Accessible (proper contrast ratios, semantic HTML, keyboard navigation)

For Tier 2 & 3 (Existing System)

• Use the project's existing component library as the primary building block
• Follow the project's file naming and directory conventions
• Use the project's CSS methodology exclusively
• Extend, don't replace: if you need a variant, extend the existing token system rather than hardcoding values
• If a component you need doesn't exist in the library, build it following the library's patterns and conventions

For Tier 1 (Greenfield)

• Choose fonts that are beautiful, unique, and interesting
• Define a cohesive color system using CSS variables
• Create a clear spacing scale
• Establish consistent component patterns
• Consider suggesting the create-design-system-rules skill to formalize the system

Frontend Aesthetics Guidelines

Typography

Tier 2 & 3: Use the project's established font stack. Create distinction through:

• Dramatic size contrasts (within the existing type scale)
• Variable font weight usage (if the project uses variable fonts)
• Creative letter-spacing and text-transform
• Line-height adjustments for visual rhythm
• If the project uses Inter, make Inter look incredible — font choice is not the only lever

Tier 1 (Greenfield):

• Choose fonts that are beautiful, unique, and interesting
• Avoid generic fonts like Arial and system defaults
• Pair a distinctive display font with a refined body font
• NEVER converge on overused choices (Space Grotesk, Inter, Roboto)

Color & Theme

Tier 2 & 3: Work within the existing palette:

• Use dominant/accent relationships with intention
• Explore the full range of the existing palette (projects often have colors defined but underused)
• Use opacity and transparency variations of existing colors for depth
• Dark/light mode: follow the project's approach

Tier 1 (Greenfield):

• Commit to a cohesive aesthetic
• Use CSS variables for consistency
• Dominant colors with sharp accents outperform timid, evenly-distributed palettes
• Vary between light and dark themes

Motion & Animation

All Tiers (this is where distinctiveness thrives regardless of design system):

• Use animations for effects and micro-interactions
• Focus on high-impact moments: page load reveals with staggered animation-delay
• Scroll-triggered animations and surprising hover states
• Purposeful transitions on state changes (loading, success, error)
• Use the project's preferred animation approach (CSS, Motion, GSAP, or framework-native)
• Prioritize CSS-only solutions for simple transitions

Spatial Composition

All Tiers (composition creativity works within any system):

• Unexpected layouts (even with standard components)
• Asymmetric arrangements of symmetric components
• Overlapping elements for depth
• Grid-breaking hero sections
• Generous negative space OR controlled density — both are valid
• Diagonal flow and visual rhythm

Backgrounds & Visual Details

Tier 2 & 3: Create atmosphere using the existing design language:

• Subtle gradients using existing palette colors
• Background patterns built from the existing token system
• Layered transparencies with existing colors
• Shadows that match the project's elevation system

Tier 1 (Greenfield):

• Gradient meshes
• Noise textures
• Geometric patterns
• Layered transparencies
• Dramatic shadows
• Decorative borders
• Custom cursors
• Grain overlays

What to AVOID

Always Avoid (All Tiers)

• Cookie-cutter layouts with no visual rhythm
• Identical components stacked without variation
• Animations that are purely decorative without purpose
• Accessibility violations (poor contrast, missing labels, no keyboard support)

Tier 2 & 3: Avoid Breaking the System

• Overriding design tokens with hardcoded values
• Importing fonts not in the project's font stack
• Creating one-off components that duplicate library components
• Using a different CSS methodology than the project's
• Introducing external dependencies without checking the project's approach
• Ignoring existing component APIs and patterns

Tier 1 (Greenfield): Avoid Generic AI Aesthetics

• Overused font families (Inter, Roboto, Arial, system fonts, Space Grotesk)
• Cliched color schemes (particularly purple gradients on white backgrounds)
• Predictable layouts and component patterns
• Generic styling that lacks context-specific character

Design Variation

• No two designs should look the same
• Even within a design system, vary how components are composed across different pages
• Apply different spatial compositions to different sections
• Interpret requirements creatively — a dashboard can be editorial, a form can be conversational, a settings page can be elegant
• The constraint of a design system should inspire more creativity, not less

Complementary Skills

• create-design-system-rules — If no design system is detected (Tier 1), suggest running this skill first to establish one. If design system rules already exist, consume and obey them.
• react-best-practices / vue-best-practices — Defer to these for framework idioms and component API patterns. This skill focuses on visual creativity, not framework best practices.
• web-design-guidelines — Use for auditing and reviewing existing interfaces against quality standards.

Remember

First, understand your room. Then, be the most creative person in that room — but do not repaint the walls if someone already chose the color.

In a greenfield project: don't hold back. Create extraordinary, distinctive work. In an existing project: create extraordinary work within the system. A PrimeVue dashboard can be breathtaking. A shadcn/ui page can be unforgettable. The design system is not a prison — it is a creative brief.