accessibility-commerce（无障碍商务）

Accessibility for E-commerce

Overview

WCAG 2.1 Level AA compliance covers screen reader announcements for dynamic cart updates, keyboard navigation for interactive components (carousels, quantity steppers, modals), focus management, and color contrast requirements. Accessible stores reduce legal risk under ADA, AODA, and EAA, and typically convert better across all users.

When to Use This Skill

• When an accessibility audit reveals WCAG violations blocking legal compliance (ADA, AODA, EAA)
• When screen reader users report inability to complete purchases
• When keyboard-only users cannot navigate the checkout flow
• When automated tools (axe, WAVE) surface critical issues that need remediation
• When building a new storefront and baking in accessibility from the start

Core Instructions

Step 1: Determine the merchant's platform and choose the right approach

Step 2: Run an accessibility audit

Before making changes, identify what needs fixing:

1. Automated scan: Run axe DevTools browser extension on your homepage, product page, cart, and checkout
2. WAVE tool: Visit wave.webaim.org and scan your store URL
3. Keyboard test: Tab through your entire checkout without a mouse — every interactive element must be reachable and operable
4. Screen reader test: Test with VoiceOver (Mac/iOS) or NVDA (Windows/Firefox) — navigate your product listing and complete a purchase

Common issues found on most stores:

• Images without meaningful alt text
• Color-only indicators (e.g., red "out of stock" with no text)
• Form fields without labels
• Modals that don't trap focus or respond to Escape
• Add-to-cart buttons that don't announce success to screen readers

Step 3: Platform-specific fixes

Shopify

Theme-level fixes (no code required):

1. Go to Online Store → Themes → Customize
2. Set alt text on all images: Products → Media → Edit alt text
3. Under Theme settings → Typography, ensure font sizes are at least 16px for body text
4. Enable Skip to content link in Header settings (available in Dawn and most modern themes)

Liquid code fixes for custom themes:

Add ARIA live region for cart updates — edit your cart-notification.liquid or equivalent snippet:

<div aria-live="polite" aria-atomic="true" class="sr-only" id="cart-live-region">
  {{ cart.item_count }} items in cart
</div>

For color swatches in variant selectors, wrap in a <fieldset> with <legend>:

<fieldset>
  <legend>{{ option.name }}: <span>{{ selected_value }}</span></legend>
  {% for value in option.values %}
    <label class="swatch {% if forloop.first %}selected{% endif %}">
      <input type="radio" name="{{ option.name }}" value="{{ value }}"
             {% if value == selected_value %}checked{% endif %} />
      <span class="sr-only">{{ value }}</span>
      <span class="swatch-color" style="background-color: {{ value | downcase }}" aria-hidden="true"></span>
    </label>
  {% endfor %}
</fieldset>

App options:

• AccessiBe (Shopify App Store, ~$49/mo) — automated WCAG 2.1 AA overlay; adds screen reader adjustments and keyboard navigation without theme edits
• EqualWeb — similar overlay approach with a free tier

WooCommerce

Plugin-based fixes:

1. Install WP Accessibility (free, wordpress.org) — adds skip navigation links, ARIA landmarks, removes title attributes from links, and fixes form labels
2. Install Accessibility Suite for WooCommerce — adds ARIA labels to cart and checkout elements automatically

Theme-based fixes:

• Use Astra or Kadence theme — both have strong WCAG AA coverage built in
• In Appearance → Customize → Typography, set base font size to 16px minimum

Manual fixes for WooCommerce checkout fields — add to your child theme's functions.php:

// Associate checkout field labels with inputs
add_filter('woocommerce_checkout_fields', function($fields) {
    foreach ($fields as $fieldset => &$fieldset_fields) {
        foreach ($fieldset_fields as $key => &$field) {
            if (!isset($field['label'])) {
                $field['label'] = ucfirst(str_replace('_', ' ', $key));
            }
        }
    }
    return $fields;
});

BigCommerce

1. Start with Cornerstone theme — it has the best baseline accessibility of all BigCommerce themes
2. Go to Storefront → My Themes → Customize and enable the accessibility settings panel
3. For color contrast: in Theme Editor, set button background color with sufficient contrast against white text (minimum 4.5:1 ratio)
4. Install an accessibility app from the BigCommerce App Marketplace (search "accessibility") for overlay-style fixes

Custom / Headless

Implement these patterns in your React/Vue/Svelte components:

ARIA live region for cart updates:

// Place once at the app root; update message after add-to-cart
export function CartLiveRegion({ message }) {
  return (
    <div role="status" aria-live="polite" aria-atomic="true"
         style={{ position: 'absolute', width: 1, height: 1, overflow: 'hidden', clip: 'rect(0,0,0,0)' }}>
      {message}
    </div>
  );
}

Accessible variant selector using radio inputs:

<fieldset>
  <legend>Color: <strong>{selectedColor}</strong></legend>
  {colors.map(color => (
    <label key={color.value} className={`swatch ${!color.available ? 'unavailable' : ''}`}>
      <input type="radio" name="color" value={color.value}
             checked={selectedColor === color.value}
             disabled={!color.available}
             onChange={() => onColorChange(color.value)}
             className="sr-only" />
      <span className="swatch-visual" style={{ background: color.hex }} aria-hidden="true" />
      <span className="sr-only">{color.label}{!color.available ? ' (out of stock)' : ''}</span>
    </label>
  ))}
</fieldset>

Focus management for modals — use native <dialog> which handles focus trapping automatically:

const dialogRef = useRef(null);
useEffect(() => {
  if (isOpen) dialogRef.current.showModal();
  else dialogRef.current.close();
}, [isOpen]);

return (
  <dialog ref={dialogRef} onClose={onClose}>
    {/* focus is automatically trapped inside <dialog> */}
    <button onClick={onClose} aria-label="Close">×</button>
    {children}
  </dialog>
);

Visible focus indicators (never remove outlines):

:focus-visible {
  outline: 3px solid #2b6cb0;
  outline-offset: 2px;
}
:focus:not(:focus-visible) { outline: none; }

Step 4: Validate and test

1. Re-run the axe scan after changes and verify critical and serious violations are resolved
2. Test keyboard navigation: Tab → all interactive elements reachable; Enter/Space → activates buttons; Escape → closes modals
3. Test with VoiceOver (Mac): Cmd + F5 to enable, navigate using Tab and arrow keys; verify cart updates are announced
4. Check color contrast with the WebAIM Contrast Checker — body text needs 4.5:1, large text 3:1

Best Practices

• Never remove focus outlines — only suppress them for mouse users with :focus:not(:focus-visible) so keyboard users retain visible focus
• Use semantic HTML first — <button> for actions, <a> for navigation, <table> for tabular data; ARIA attributes cannot fix non-semantic markup
• Test with a real screen reader — automated tools catch only 30-40% of real issues; NVDA+Firefox and VoiceOver+Safari are the most common combinations
• Make touch targets at least 44×44px — this also benefits motor-impaired mouse users
• Write descriptive button text — "Add to Cart" is fine; "Click here" is not; screen reader users navigate by button and link text
• Caption all product videos — use auto-captions as a starting point but verify accuracy for product names and pricing

Common Pitfalls

Related Skills

• @responsive-storefront
• @checkout-flow-optimization
• @mega-menu-builder
• @search-autocomplete