Web Design Builder

Web Design Builder

This skill creates professional HTML5/JavaScript web designs from specifications, with automatic accessibility and functionality verification using Playwright MCP.

When to Use This Skill

Activate this skill when the user requests:

• Create a web design from a specification or description
• Build a landing page, website, or web application
• Create a design mockup or prototype
• Refactor or improve existing HTML/CSS/JavaScript code
• Build responsive web interfaces
• Create component libraries or design systems
• Generate accessible web designs with WCAG compliance

Core Workflow

Phase 1: Requirements Gathering

When a user requests a web design, start by understanding their needs:

1. Clarify the Design Scope

• What type of design? (landing page, dashboard, form, etc.)
• Target audience and use case
• Required features and functionality
• Content and copy (provided or placeholder?)
• Brand colors, fonts, or design system
• Responsive requirements (mobile-first?)

1. Technical Preferences

• Framework preference:
• Vanilla HTML/CSS/JS (simple, no dependencies)
• Tailwind CSS (utility-first, recommended for rapid development)
• React (component-based, for complex interactions)
• Vue (progressive framework)
• Alpine.js (lightweight reactivity)
• Browser support requirements
• Accessibility requirements (WCAG level)
• Performance constraints

1. Check Playwright MCP Availability

IMPORTANT: Before starting the design process, check if Playwright MCP is available:

   // Check if mcp__playwright tools are available
   // Look for tools like: mcp__playwright__navigate, mcp__playwright__screenshot, etc.

If Playwright MCP is NOT available:

• Inform the user: "Playwright MCP is not installed. Design verification will be skipped."
• Provide installation instructions (see MCP Setup section below)
• Continue with design generation but skip verification phase
• Mark this clearly in the output

If Playwright MCP IS available:

• Inform the user: "Playwright MCP detected. Design will be automatically verified."
• Include verification in the workflow

Phase 2: Design Generation

Step 1: Create Design Mockup

Generate a complete HTML/CSS/JS mockup including:

HTML Structure:

• Semantic HTML5 elements
• Proper heading hierarchy (h1 → h6)
• ARIA landmarks (header, nav, main, aside, footer)
• Accessible form labels and inputs
• Alt text for images
• Unique page title

CSS Styling:

• Responsive design (mobile-first)
• CSS Grid or Flexbox for layouts
• Custom properties (CSS variables) for theming
• Smooth transitions and animations
• Print styles (if applicable)
• Dark mode support (optional)

JavaScript Functionality:

• Progressive enhancement
• Accessible interactions (keyboard support)
• Form validation
• Dynamic content loading
• Event handling
• Error handling

Accessibility Features:

• WCAG 2.1 Level AA compliance minimum
• Keyboard navigation support
• Focus indicators
• Screen reader friendly
• Color contrast compliance (4.5:1 minimum)
• Skip links
• ARIA attributes where needed

Example Output Structure:

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Page Title</title>
  <style>
    /* Modern CSS with custom properties */
    :root {
      --primary-color: #0066cc;
      --text-color: #1a1a1a;
      --bg-color: #ffffff;
      --spacing: 1rem;
    }

    /* Reset and base styles */
    *, *::before, *::after {
      box-sizing: border-box;
      margin: 0;
      padding: 0;
    }

    body {
      font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
      line-height: 1.6;
      color: var(--text-color);
      background: var(--bg-color);
    }

    /* Responsive layout */
    @media (max-width: 768px) {
      /* Mobile styles */
    }
  </style>
</head>
<body>
  <!-- Accessible skip link -->
  <a href="#main-content" class="skip-link">Skip to main content</a>

  <!-- Semantic structure -->
  <header role="banner">
    <nav aria-label="Main navigation">
      <!-- Navigation -->
    </nav>
  </header>

  <main id="main-content" role="main">
    <!-- Main content -->
  </main>

  <footer role="contentinfo">
    <!-- Footer -->
  </footer>

  <script>
    // Progressive enhancement JavaScript
    (function() {
      'use strict';

      // Feature detection
      if (!('querySelector' in document)) return;

      // Your JavaScript here
    })();
  </script>
</body>
</html>

Step 2: Save Design to File

Save the generated design to a file:

// Recommended file structure
project-name/
  index.html         // Main HTML file
  styles.css         // Separate CSS (if needed)
  script.js          // Separate JS (if needed)
  assets/
    images/          // Image assets
    fonts/           // Custom fonts

Use the Write tool to create the file:

• Save to user's current directory or ask for preferred location
• Use descriptive filename (e.g., landing-page.html, dashboard.html)
• Create single-file HTML for mockups (CSS/JS inline)
• Create separate files for production builds

Phase 3: Design Verification (ONLY if Playwright MCP is available)

IMPORTANT: Only execute this phase if Playwright MCP was detected in Phase 1.

Step 1: Launch Browser and Load Design

Use Playwright MCP to open the design:

// Navigate to the local HTML file
await mcp__playwright__navigate({
  url: 'file:///path/to/design.html'
});

Step 2: Accessibility Testing

Run comprehensive accessibility checks:

1. Automated Accessibility Scan

• Check for WCAG violations
• Verify color contrast ratios
• Check heading hierarchy
• Verify ARIA attributes
• Check form labels
• Verify alt text on images

1. Keyboard Navigation Test

• Tab through all interactive elements
• Verify focus indicators are visible
• Check tab order is logical
• Test Escape key behavior (modals, dropdowns)
• Verify no keyboard traps

1. Screen Reader Compatibility

• Check ARIA landmarks
• Verify semantic HTML usage
• Check dynamic content announcements
• Verify form error messages

Step 3: Visual Testing

Capture screenshots and verify layout:

// Take full-page screenshot
await mcp__playwright__screenshot({
  fullPage: true,
  path: 'design-screenshot.png'
});

// Test responsive breakpoints
const breakpoints = [
  { width: 375, height: 667, name: 'mobile' },
  { width: 768, height: 1024, name: 'tablet' },
  { width: 1440, height: 900, name: 'desktop' }
];

for (const bp of breakpoints) {
  await mcp__playwright__setViewportSize({
    width: bp.width,
    height: bp.height
  });

  await mcp__playwright__screenshot({
    path: `design-${bp.name}.png`
  });
}

Step 4: Functionality Testing

Test interactive elements:

1. Form Validation

• Test required fields
• Test input validation
• Test error messages
• Test success states

1. Interactive Components

• Test buttons and links
• Test modals and dialogs
• Test dropdowns and menus
• Test tabs and accordions
• Test carousels and sliders

1. JavaScript Functionality

• Verify event handlers work
• Test dynamic content loading
• Check console for errors
• Verify progressive enhancement

Step 5: Performance Check

Evaluate performance metrics:

1. Load Time

• Measure page load time
• Check resource loading
• Identify bottlenecks

1. Resource Optimization

• Check CSS file size
• Check JavaScript file size
• Verify image optimization
• Check for unused CSS/JS

Phase 4: Verification Report

Generate a comprehensive report:

# Design Verification Report

## Overview