web-design-guidelines

name	web-design-guidelines
description	Visual inspection and code review for Web Interface Guidelines compliance. Triggers on "review my UI", "check accessibility", "audit design", "review UX", "fix the layout", "find design problems". Supports both static code analysis and visual browser inspection with auto-fixing.
metadata	{"author":"vercel","version":"2.0.0","argument-hint":"<url-or-file-pattern>"}

Web Interface Guidelines

Review and fix UI for compliance with Web Interface Guidelines through static code analysis and visual browser inspection.

Scope of Application

• Static sites (HTML/CSS/JS)
• SPA frameworks: React / Vue / Angular / Svelte
• Full-stack frameworks: Next.js / Nuxt / SvelteKit
• Any web application with accessible source code

Workflow Overview

Step 1: Information Gathering
    ↓
Step 2: Guidelines Fetch + Static Analysis
    ↓
Step 3: Visual Inspection (if URL provided)
    ↓
Step 4: Issue Fixing
    ↓
Step 5: Re-verification
    ↓
(Loop if issues remain)

---

Step 1: Information Gathering

1.1 Determine Review Mode

Input	Mode	Actions
File/pattern only	Static Analysis	Code review against guidelines
URL only	Visual Inspection	Browser-based visual review
URL + files	Full Review	Both static and visual analysis

1.2 URL Confirmation (Visual Mode)

If visual inspection requested but no URL provided, ask:

Please provide the URL of the website to review (e.g., http://localhost:3000)

1.3 Project Detection

Attempt automatic detection from workspace files:

File	Detection
package.json	Framework and dependencies
tailwind.config.*	Tailwind CSS
next.config.*	Next.js
nuxt.config.*	Nuxt
vite.config.*	Vite

1.4 Styling Method Identification

Method	Detection	Edit Target
Pure CSS	*.css files	Global or component CSS
SCSS/Sass	*.scss, *.sass	SCSS files
CSS Modules	*.module.css	Module CSS files
Tailwind CSS	tailwind.config.*	className in components
styled-components	styled. in code	JS/TS files
CSS-in-JS	Inline styles	JS/TS files

---

Step 2: Guidelines Fetch + Static Analysis

2.1 Fetch Latest Guidelines

Fetch fresh guidelines before each review:

https://raw.githubusercontent.com/vercel-labs/web-interface-guidelines/main/command.md

Use WebFetch to retrieve the latest rules. The fetched content contains all the rules and output format instructions.

2.2 Static Code Analysis

1. Read the specified files (or prompt user for files/pattern)
2. Check against all rules in the fetched guidelines
3. Collect findings with file:line references

---

Step 3: Visual Inspection (Browser Mode)

3.1 Prerequisites

• Target website must be running (local dev server or remote)
• Browser automation available (Playwright MCP or cursor-browser-extension)

3.2 Page Inspection

1. Navigate to the specified URL
2. Capture screenshots
3. Retrieve DOM structure/snapshot
4. If additional pages exist, traverse through navigation

3.3 Viewport Testing

Test at the following viewports for responsive issues:

Name	Width	Representative Device
Mobile	375px	iPhone SE/12 mini
Tablet	768px	iPad
Desktop	1280px	Standard PC
Wide	1920px	Large display

3.4 Visual Inspection Checklist

Layout Issues

Issue	Description	Severity
Element Overflow	Content overflows container or viewport	High
Element Overlap	Unintended overlapping of elements	High
Alignment Issues	Grid or flex alignment problems	Medium
Inconsistent Spacing	Padding/margin inconsistencies	Medium
Text Clipping	Long text not handled properly	Medium

Responsive Issues

Issue	Description	Severity
Non-mobile Friendly	Layout breaks on small screens	High
Breakpoint Issues	Unnatural transitions at breakpoints	Medium
Touch Targets	Buttons too small on mobile	Medium

Accessibility Issues

Issue	Description	Severity
Insufficient Contrast	Low contrast ratio text/background	High
No Focus State	Cannot see focus during keyboard nav	High
Missing alt Text	No alternative text for images	Medium

Visual Consistency

Issue	Description	Severity
Font Inconsistency	Mixed font families	Medium
Color Inconsistency	Non-unified brand colors	Medium
Spacing Inconsistency	Non-uniform spacing patterns	Low

---

Step 4: Issue Fixing

4.1 Issue Prioritization

Priority	Criteria	Action
P1	Layout issues affecting functionality	Fix immediately
P2	Visual issues degrading UX	Fix next
P3	Minor visual inconsistencies	Fix if possible

4.2 Identifying Source Files

1. Selector-based Search: Search codebase by class name or ID
2. Component-based Search: Identify components from element text/structure
3. File Pattern Filtering: src/**/*.css, styles/**/*, src/components/**/*

4.3 Fix Principles

1. Minimal Changes: Only make minimum changes necessary
2. Respect Existing Patterns: Follow existing code style
3. Avoid Breaking Changes: Be careful not to affect other areas
4. Add Comments: Explain reason for fixes where appropriate

---

Step 5: Re-verification

5.1 Post-fix Confirmation

1. Reload browser (or wait for HMR)
2. Capture screenshots of fixed areas
3. Compare before and after

5.2 Regression Testing

• Verify fixes haven't affected other areas
• Confirm responsive display is not broken

5.3 Iteration

If issues remain after fix, return to Step 3. Limit to 3 fix attempts per issue before consulting user.

---

Output Format

Review Results Report

# Web Design Review Results

## Summary

| Item | Value |
|------|-------|
| Target | {URL or files} |
| Framework | {Detected framework} |
| Styling | {CSS / Tailwind / etc.} |
| Review Mode | {Static / Visual / Full} |
| Issues Detected | {N} |
| Issues Fixed | {M} |

## Static Analysis Findings

{file:line format findings from guidelines check}

## Visual Inspection Findings

### [P1] {Issue Title}

- **Page**: {Page path}
- **Element**: {Selector or description}
- **Issue**: {Detailed description}
- **Fixed File**: `{File path}`
- **Fix Details**: {Description of changes}

### [P2] {Issue Title}
...

## Unfixed Issues (if any)

### {Issue Title}
- **Reason**: {Why it was not fixed}
- **Recommended Action**: {Recommendations for user}

## Recommendations

- {Suggestions for future improvements}

---

Usage Examples

Static Analysis Only

Review my UI in src/components/
Check accessibility of my forms
Audit design of src/pages/

Visual Inspection

Review the design at http://localhost:3000
Check the UI at http://localhost:5173/dashboard
Find layout problems on my site

Full Review (Recommended)

Review my UI at localhost:3000 and fix issues in src/
Audit the design and fix responsive problems

---

Best Practices

DO

• Always save screenshots before making fixes
• Fix one issue at a time and verify each
• Follow the project's existing code style
• Confirm with user before major changes

DON'T

• Large-scale refactoring without confirmation
• Ignore design systems or brand guidelines
• Fix multiple issues at once (difficult to verify)
• Skip re-verification after fixes

---

Troubleshooting

Style files not found

1. Check dependencies in package.json
2. Consider CSS-in-JS possibility
3. Ask user about styling method

Fixes not reflected

1. Check if dev server HMR is working
2. Clear browser cache
3. Check CSS specificity issues

Fixes affecting other areas

1. Rollback changes
2. Use more specific selectors
3. Consider CSS Modules or scoped styles