frontend-enhancer — Claude Code skill for Next.js UI work

---
name: frontend-enhancer
description: This skill should be used when enhancing the visual design and aesthetics of Next.js web applications. It provides modern UI components, design patterns, color palettes, animations, and layout templates. Use this skill for tasks like improving styling, creating responsive designs, implementing modern UI patterns, adding animations, selecting color schemes, or building aesthetically pleasing frontend interfaces.
---

# Frontend Enhancer

## Overview

The Frontend Enhancer skill transforms Next.js applications into visually stunning, modern web experiences. It provides production-ready components, comprehensive design guidelines, curated color palettes, smooth animations, and flexible layout templates optimized for responsiveness and accessibility.

## When to Use This Skill

Invoke this skill when:
- Improving the visual appearance of an existing application
- Creating new UI components with modern styling
- Selecting color schemes and design themes
- Adding animations and transitions
- Building responsive layouts for different screen sizes
- Implementing hero sections, feature grids, or landing pages
- Enhancing user experience with better visual hierarchy
- Applying consistent design patterns across an application

## Core Capabilities

### 1. Component Library

Use pre-built, production-ready React components with multiple variants and states:

**Button Component** (`assets/button-variants.tsx`):
- Variants: primary, secondary, outline, ghost, danger
- Sizes: sm, md, lg
- Loading states with animated spinner
- Full TypeScript support
- Accessibility features built-in

**Card Component** (`assets/card-variants.tsx`):
- Variants: default, bordered, elevated, interactive
- Subcomponents: CardHeader, CardTitle, CardDescription, CardContent, CardFooter
- Hover effects and transitions
- Flexible padding options

**Input Components** (`assets/input-variants.tsx`):
- Text inputs with validation states
- Textarea component
- Left/right icon support
- Error and helper text display
- Label integration
- Full accessibility support

**Implementation workflow:**
1. Copy the desired component file from `assets/` to your project's components directory
2. Ensure the `cn` utility function exists (see `assets/utils-cn.ts`)
3. Customize colors, spacing, or variants to match your brand
4. Import and use the component in your pages

### 2. Layout Templates

Use pre-designed, responsive layout patterns for common page sections:

**Hero Section** (`assets/layout-hero-section.tsx`):
- Three variants: centered, split, minimal
- Support for CTAs (primary and secondary)
- Optional background gradients
- Image/illustration support
- Built-in animations

**Feature Grid** (`assets/layout-feature-grid.tsx`):
- Configurable columns (2, 3, or 4)
- Icon integration
- Staggered animations
- Hover effects
- Fully responsive

**Implementation workflow:**
1. Copy the layout component from `assets/` to your components directory
2. Customize the props and content to match your needs
3. Integrate with your existing pages
4. Adjust styling as needed for your brand

### 3. Design System Guidelines

Reference comprehensive design principles for consistent, professional interfaces:

**Design Principles** (`references/design_principles.md`):
- Visual hierarchy best practices
- Spacing and rhythm guidelines
- Typography recommendations
- Color theory and usage
- Consistency standards
- Responsiveness strategies
- Accessibility guidelines (WCAG AA/AAA)
- Common layout patterns

**When to reference:**
- Starting a new design
- Making decisions about visual hierarchy
- Ensuring accessibility compliance
- Establishing consistency across the app
- Reviewing design quality

**How to use:**
Read `references/design_principles.md` to understand best practices, then apply them to your specific design challenges. The document covers both theory and practical implementation.

### 4. Color Palettes

Access professionally curated color schemes optimized for modern web applications:

**Available Palettes** (`references/color_palettes.md`):
1. **Corporate Blue** - Professional, trustworthy (business apps, SaaS)
2. **Vibrant Purple** - Creative, modern (creative tools, portfolios)
3. **Minimalist Gray** - Clean, sophisticated (minimalist designs)
4. **Warm Sunset** - Energetic, friendly (consumer apps, e-commerce)
5. **Ocean Fresh** - Calm, professional (health, finance apps)
6. **Dark Mode** - Modern, eye-friendly (developer tools, dashboards)

Each palette includes:
- Primary and secondary colors
- Accent colors
- Background and surface colors
- Text colors (primary and secondary)
- Semantic colors (success, warning, error)
- Border colors

**Implementation options:**
1. **Tailwind CSS**: Add colors to `tailwind.config.js` (examples provided)
2. **CSS Variables**: Use custom properties in global CSS (examples provided)
3. **Inline styles**: Reference hex codes directly in components

**Selection workflow:**
1. Review `references/color_palettes.md` to see all available palettes
2. Consider your application's purpose and brand identity
3. Choose a palette that matches your goals
4. Implement using Tailwind config or CSS variables
5. Adjust specific colors if needed to match your brand

### 5. Animations and Transitions

Add smooth, professional animations using pre-built CSS classes and keyframes:

**Animation Library** (`assets/animations.css`):
- Fade animations (fadeIn, fadeOut, fadeInUp, fadeInDown)
- Slide animations (slideInLeft, slideInRight)
- Scale animations (scaleIn, scaleOut)
- Utility animations (bounce, pulse, spin)
- Skeleton loading (shimmer effect)
- Hover effects (lift, glow, scale)
- Stagger delays for list animations

**Accessibility:**
All animations respect `prefers-reduced-motion` for accessibility compliance.

**Implementation workflow:**
1. Copy `assets/animations.css` to your global CSS file (or create a separate animations file)
2. Apply utility classes like `animate-fade-in-up`, `hover-lift`, etc.
3. Use stagger classes for sequential animations in lists
4. Customize duration and easing if needed

**Best practices:**
- Keep animations subtle (200-300ms for micro-interactions)
- Use animations to guide user attention
- Avoid excessive motion that distracts
- Always test with `prefers-reduced-motion` enabled

## Enhancement Workflow

Follow this systematic approach when enhancing a frontend application:

### Step 1: Assess Current State
- Identify areas lacking visual polish
- Note inconsistent styling patterns
- Check responsive behavior
- Review accessibility issues
- Evaluate color scheme and typography

### Step 2: Select Design Direction
- Choose a color palette from `references/color_palettes.md`
- Review design principles in `references/design_principles.md`
- Decide on component variants and styles
- Plan layout improvements

### Step 3: Implement Foundation
- Set up the `cn` utility function (`assets/utils-cn.ts`)
- Configure chosen color palette (Tailwind or CSS variables)
- Add animation CSS (`assets/animations.css`) to global styles
- Ensure consistent spacing scale

### Step 4: Apply Components
- Replace basic elements with enhanced components from `assets/`
- Implement layout templates for key pages
- Apply consistent styling across the application
- Add animations and transitions

### Step 5: Refine and Polish
- Test responsiveness across device sizes
- Verify accessibility (keyboard navigation, contrast, screen readers)
- Ensure consistent hover/focus states
- Optimize performance (check animation performance)
- Test with `prefers-reduced-motion`

### Step 6: Final Review
- Check visual hierarchy on all pages
- Verify color consistency
- Test all interactive states
- Validate responsive breakpoints
- Review accessibility compliance

## Utility Function Setup

Most components require the `cn` utility function for class name merging. To set it up:

1. Copy `assets/utils-cn.ts` to your project's `lib/utils.ts`
2. Install dependencies:
   ```bash
   npm install clsx tailwind-merge
   ```
3. Import in components:
   ```typescript
   import { cn } from '@/lib/utils';
   ```

## Responsive Design Strategy

All components and layouts follow a mobile-first approach:

1. **Base styles** - Optimized for mobile (320px+)
2. **sm breakpoint** - Small tablets (640px+)
3. **md breakpoint** - Tablets (768px+)
4. **lg breakpoint** - Desktops (1024px+)
5. **xl breakpoint** - Large desktops (1280px+)

Test each breakpoint to ensure proper layout and readability.

## Accessibility Checklist

Ensure all enhanced interfaces meet these standards:

- [ ] Color contrast meets WCAG AA (4.5:1 for text)
- [ ] All interactive elements are keyboard accessible
- [ ] Focus indicators are visible and clear
- [ ] Semantic HTML is used (nav, main, article, etc.)
- [ ] Images have alt text
- [ ] Forms have proper labels
- [ ] Animations respect prefers-reduced-motion
- [ ] Touch targets are at least 44x44px

## Customization Guide

To adapt components and templates to your brand:

1. **Colors**: Update color values in palette config or component files
2. **Typography**: Adjust font sizes, weights, and families
3. **Spacing**: Modify padding and margin values
4. **Border Radius**: Change rounded corners (e.g., `rounded-lg` to `rounded-xl`)
5. **Shadows**: Adjust shadow intensity (e.g., `shadow-md` to `shadow-lg`)
6. **Animations**: Modify duration and easing functions

## Resources Summary

This skill includes:

### references/
- `color_palettes.md` - Six professionally designed color schemes with implementation examples
- `design_principles.md` - Comprehensive design guidelines covering visual hierarchy, typography, accessibility, and common patterns

### assets/
- `button-variants.tsx` - Modern button component with 5 variants and 3 sizes
- `card-variants.tsx` - Flexible card component with subcomponents
- `input-variants.tsx` - Input and textarea components with validation states
- `layout-hero-section.tsx` - Hero section with 3 layout variants
- `layout-feature-grid.tsx` - Responsive feature grid with configurable columns
- `animations.css` - Complete animation library with accessibility support
- `utils-cn.ts` - Utility function for class name merging

## Tips for Success

1. **Start with a plan**: Review design principles before making changes
2. **Choose one palette**: Stick to a single color scheme for consistency
3. **Test on real devices**: Emulators don't always show true responsive behavior
4. **Keep it simple**: Modern design favors simplicity over complexity
5. **Prioritize accessibility**: Design for all users from the start
6. **Iterate based on feedback**: Show designs to users and refine
7. **Maintain consistency**: Use the same patterns throughout your application
8. **Performance matters**: Keep animations smooth (60fps) and optimize images

## Common Use Cases

### Enhancing an Existing App
1. Select a color palette and implement it
2. Replace basic buttons/inputs with enhanced components
3. Add subtle animations to improve feedback
4. Review and improve spacing consistency
5. Ensure responsive behavior across devices

### Building a Landing Page
1. Use hero section layout as the focal point
2. Add feature grid to showcase key features
3. Implement consistent button styles for CTAs
4. Add staggered animations for visual interest
5. Test responsiveness thoroughly

### Creating a Dashboard
1. Use card components for data sections
2. Implement consistent spacing and hierarchy
3. Choose a professional color palette
4. Add skeleton loaders for data fetching
5. Ensure touch-friendly controls on mobile

### Redesigning Forms
1. Replace inputs with enhanced input components
2. Add clear error and validation states
3. Ensure proper label associations
4. Implement loading states for submission
5. Test keyboard navigation flow