Frontend Analyzer

Analisa e identifica tipografia, cores, layout, fontes e elementos de design system em componentes frontend.

Overview

The Frontend Analyzer skill provides deep inspection of frontend code, design elements, and visual properties. It extracts typography, color palettes, spacing systems, component hierarchies, and accessibility attributes from React/Next.js applications.

Core Capabilities

1. Visual Element Analysis

🔤 Typography Detection

• Font families (system fonts, Google Fonts, custom fonts)
• Font sizes and scaling systems (rem, px, %)
• Font weights (100-900)
• Line heights and letter spacing
• Text decorations and text transforms
• Font loading strategies (WOFF2, variable fonts)

🎨 Color Palette Extraction

• Primary, secondary, accent colors
• Background and text colors
• Semantic colors (success, error, warning, info)
• Opacity/alpha values
• Color space (RGB, HSL, hex, CSS variables)
• Dark mode variants

📐 Layout & Spacing

• Grid systems (CSS Grid, Flexbox)
• Spacing scale (gaps, margins, padding)
• Breakpoints and responsive behavior
• Container queries and fluid sizing
• Z-index hierarchy
• Positioning strategies

🧩 Component Architecture

• Component hierarchy and nesting
• Reusable component patterns
• Props and TypeScript interfaces
• State management patterns
• Custom hooks usage
• Styled components vs CSS modules

2. Analysis Categories

1. Visual Inspection - Screenshots and visual differences
2. Code Inspection - Component code structure
3. Design System - Design token usage
4. Accessibility (A11y) - WCAG AA/AAA compliance
5. Performance - Font loading optimization

Analysis Output Structure

## 🎨 VISUAL ELEMENTS DETECTED

### Typography System
- Primary Font: [Font family, source, fallback]
- Heading Scale: H1-H6 sizes and weights
- Body Text: Default size, line-height, letter-spacing
- Monospace: Code/terminal fonts

### Color Palette
- Primary: #XXXXXX (RGB, HSL, CSS var)
- Semantic: Success, error, warning colors
- Dark Mode: Color scheme variants
- Contrast Ratios: WCAG AA/AAA compliance

### Layout System
- Grid: [Columns, gap, max-width]
- Breakpoints: [Mobile, tablet, desktop specs]
- Spacing Scale: [Base unit, multipliers]

Usage Examples

Example 1: Extract Design Tokens

Input: "Analise tipografia de ofertachina.com" Output: All fonts used, sizes, weights, loading strategy

Example 2: Color Palette Analysis

Input: "Extraia paleta de cores do ProductCard" Output: Exact colors, WCAG compliance, dark mode variants

Example 3: Component Deep Dive

Input: "Analise estrutura de ProductCard" Output: JSX structure, props, styling approach, accessibility

Example 4: Design System Audit

Input: "Audite design system compliance" Output: % compliance, violations, refactoring recommendations

Accessibility (WCAG)

• Contrast ratios: Pass/Fail by element
• Font sizes: Minimum sizes met
• Interactive elements: Size compliance
• Semantic HTML: Structure quality

Performance Metrics

• Font file sizes and optimization
• Image optimization status
• CSS bundle size
• Component render efficiency

Integrations

With the integrated browser

• Automated visual analysis
• Color & typography extraction
• Accessibility testing

With Prompt Improver

• Design tokens inform prompt creation
• UI patterns documented in instructions

Tools & Technologies Reference

• CSS Analysis: PostCSS, cssstats
• Typography: Google Fonts API, Font loading APIs
• Color: Chroma.js, ntc.js (color naming)
• Accessibility: axe-core, WAVE
• React Inspection: React DevTools, Storybook
• Design Systems: Figma API, Design tokens parser

References

• Google Fonts
• Tailwind CSS Documentation
• WCAG Color Contrast Checker
• CSS-Tricks
• MDN Web Docs
• Figma Design System

Changelog

• v1.0 (2025-12-19): Initial release with typography, color, layout, component, and accessibility analysis

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Appendix: Web UI Analysis

Detailed UX and accessibility analysis for web interfaces.

When to Use

Use this section when:

• Evaluating a web interface for UX issues
• Checking accessibility compliance (WCAG 2.1 AA/AAA)
• Analyzing color contrast ratios
• Reviewing typography and font hierarchy
• Checking responsive design breakpoints
• Measuring Core Web Vitals (LCP, FID, CLS)
• Comparing against Material Design or Apple HIG standards

Analysis Framework

1. Accessibility (WCAG 2.1)

✅ Checklist:
- [ ] Color contrast ratio ≥ 4.5:1 (text), ≥ 3:1 (large text)
- [ ] Touch targets ≥ 44x44px
- [ ] Keyboard navigation works
- [ ] Screen reader labels present
- [ ] Focus states visible
- [ ] Alt text on images
- [ ] ARIA roles correct

2. Typography Hierarchy

Heading Scale (1.250 ratio):
- h1: 2.441rem (39px)
- h2: 1.953rem (31px)
- h3: 1.563rem (25px)
- h4: 1.25rem (20px)
- body: 1rem (16px)
- small: 0.8rem (13px)

3. Color Palette Analysis

Primary Colors:
- Main: #hex (contrast ratio)
- Light variant: #hex
- Dark variant: #hex

Semantic Colors:
- Success: #22c55e (green-500)
- Warning: #f59e0b (amber-500)
- Error: #ef4444 (red-500)
- Info: #3b82f6 (blue-500)

4. Layout & Spacing

8px Grid System:
- xs: 4px (0.25rem)
- sm: 8px (0.5rem)
- md: 16px (1rem)
- lg: 24px (1.5rem)
- xl: 32px (2rem)
- 2xl: 48px (3rem)

Breakpoints:
- mobile: 0-639px
- tablet: 640-1023px
- desktop: 1024-1279px
- wide: 1280px+

5. Core Web Vitals

Targets:
- LCP (Largest Contentful Paint): < 2.5s
- FID (First Input Delay): < 100ms
- CLS (Cumulative Layout Shift): < 0.1
- FCP (First Contentful Paint): < 1.8s
- TTFB (Time to First Byte): < 0.8s

Output Format

## UI Analysis Report

### Summary
- Overall Score: X/100
- Accessibility: ✅/⚠️/❌
- Performance: ✅/⚠️/❌
- Responsive: ✅/⚠️/❌

### Critical Issues
1. [Issue] - [Impact] - [Fix]

### Recommendations
1. [Improvement] - [Code example]

### Resources
- [Link to relevant docs]

Example Usage

@frontend Analyze the login page for accessibility issues
@frontend Check color contrast on the dashboard
@frontend Review typography hierarchy on landing page
@frontend Measure Core Web Vitals for homepage