<!-- ❌ CRITICAL: No alt text -->
<img src="chart.png">

<!-- ❌ CRITICAL: Non-semantic button -->
<div onclick="submit()">Submit</div>

<!-- ❌ HIGH: Color-only information -->
<span style="color: red">Required</span>

<!-- ❌ HIGH: No form label -->
<input type="email" placeholder="Email">

<!-- ❌ HIGH: Hidden focus state -->
*:focus { outline: none; }

<!-- ❌ MEDIUM: Auto-playing media -->
<video autoplay>

<!-- ❌ HIGH: No loading state -->
<button onclick="slowAction()">Save</button>
<!-- User has no idea if click worked -->

<!-- ❌ HIGH: No error explanation -->
<input class="error">  <!-- Why is it error? -->

<!-- ❌ HIGH: Destructive action without confirm -->
<button onclick="deleteAll()">Delete All</button>

<!-- ❌ MEDIUM: Tiny touch target -->
<a style="font-size: 10px;">Click me</a>

/* ❌ HIGH: Hardcoded values */
padding: 13px;  /* Should use spacing token */
font-size: 15px;  /* Should use type scale */
color: #337ab7;  /* Should use color token */

/* ❌ MEDIUM: Inconsistent spacing */
.card { padding: 16px; }
.card-similar { padding: 20px; }  /* Why different? */

<!-- ✅ Semantic, keyboard accessible, described -->
<button
  type="submit"
  aria-label="Submit contact form"
  disabled={isSubmitting}
>
  {isSubmitting ? 'Submitting...' : 'Submit'}
</button>

<!-- ✅ Labeled, described, with error handling -->
<div class="field">
  <label for="email">
    Email address
    <span aria-hidden="true">*</span>
  </label>
  <input
    type="email"
    id="email"
    required
    aria-required="true"
    aria-describedby="email-hint email-error"
    aria-invalid={hasError}
  >
  <span id="email-hint" class="hint">
    We'll never share your email.
  </span>
  {hasError && (
    <span id="email-error" class="error" role="alert">
      Please enter a valid email address.
    </span>
  )}
</div>

<!-- ✅ Informative image with description -->
<img
  src="sales-chart.png"
  alt="Sales chart showing 25% growth in Q4 2024"
>

<!-- ✅ Decorative image (skip for screen readers) -->
<img src="decorative-line.png" alt="" role="presentation">

<!-- ✅ Skip to main content for keyboard users -->
<a href="#main" class="skip-link">
  Skip to main content
</a>

<style>
.skip-link {
  position: absolute;
  top: -40px;
  left: 0;
  padding: 8px;
  background: #000;
  color: #fff;
  z-index: 100;
}
.skip-link:focus {
  top: 0;
}
</style>

/* ✅ Visible, high-contrast focus indicator */
:focus {
  outline: 2px solid #005fcc;
  outline-offset: 2px;
}

/* ✅ Only hide for mouse users */
:focus:not(:focus-visible) {
  outline: none;
}
:focus-visible {
  outline: 2px solid #005fcc;
  outline-offset: 2px;
}

# Accessibility testing
npx axe-core-cli <url>             # Automated a11y scan
npx pa11y <url>                    # Page accessibility
npx lighthouse <url> --view        # Full audit

# Visual testing
npx storybook                      # Component testing
npx chromatic                      # Visual regression

# Validation
npx html-validate <file>           # HTML validation