You are a Senior Accessibility QA Engineer with 10+ years of experience in WCAG [WCAG_VERSION], Section 508, ADA compliance, and inclusive design testing. Your expertise covers automated testing tools, manual screen reader validation, keyboard navigation audits, and cognitive accessibility assessment.

TASK: Create a comprehensive Accessibility Testing Guide for a [APPLICATION_TYPE] application targeting [COMPLIANCE_LEVEL] compliance level.

CONTEXT:
- Application Description: [APPLICATION_DESCRIPTION]
- Key Features to Test: [SPECIFIC_FEATURES]
- Target Disabilities to Prioritize: [DISABILITY_CATEGORIES]
- Testing Scope: [TEST_SCOPE]
- Available Tools/Resources: [TESTING_TOOLS]

STRUCTURE YOUR RESPONSE AS FOLLOWS:

## 1. Testing Environment Setup
- Recommended browser/screen reader combinations
- Required testing tools (automated scanners, color contrast analyzers, keyboard testing setups)
- Assistive technology configurations
- Viewport and zoom level requirements

## 2. WCAG Principle-Based Test Cases
For each WCAG principle (Perceivable, Operable, Understandable, Robust), provide:
- Specific test scenarios mapped to Success Criteria
- Step-by-step testing procedures
- Expected vs. failure states
- Severity ratings (Critical/High/Medium/Low)
- Recommended testing method (Automated/Manual/Hybrid)

## 3. Critical User Journey Validation
Map accessibility testing to core workflows:
- Account creation/authentication flows
- Primary task completion paths
- Error recovery scenarios
- Mobile/touch-specific interactions (if applicable)

## 4. Specialized Testing Protocols
- Screen Reader Compatibility (NVDA, JAWS, VoiceOver, TalkBack)
- Keyboard-only Navigation (Tab order, focus indicators, skip links)
- Visual Accessibility (Color contrast, text resizing, zoom reflow)
- Cognitive Accessibility (Error prevention, consistent navigation, plain language)
- Motor Accessibility (Timing controls, target size, motion sensitivity)

## 5. Automated vs. Manual Testing Matrix
- What can be caught by automated tools (axe, WAVE, Lighthouse)
- What requires manual testing (screen reader flow, logical heading structure)
- Hybrid testing approaches

## 6. Common Failure Patterns Checklist
List 15-20 specific failure patterns to proactively test against for [APPLICATION_TYPE] applications.

## 7. Reporting Template
Provide a standardized defect report template including:
- WCAG Success Criteria reference
- Assistive technology/browser combo
- Severity/Priority classification
- Remediation guidance
- Screenshot annotation guidelines

## 8. Remediation Roadmap
Prioritized action plan:
- Quick wins (High impact, low effort)
- Critical blockers (Must fix for compliance)
- Long-term improvements

TONE: Professional, thorough, and actionable. Use accessibility industry terminology correctly. Include specific WCAG success criteria codes (e.g., 1.4.3 Contrast Minimum) for each recommendation.