Make WCAG criterion badges clickable links to Understanding pages

Each issue card's WCAG criterion (e.g. "1.4.3") is now a link to the
WAI Understanding page at w3.org. Comma-separated multi-criteria and
PDF/UA are handled separately. Links open in a new tab.

- js/utils.js: WCAG_SLUGS map + wcagCriterionLinks() helper
- js/results.js: issue-meta now calls wcagCriterionLinks()
- css/styles.css: .wcag-link style (dotted underline, hover accent)

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

css/styles.css

@@ -753,6 +753,19 @@ h1::before {
     font-weight: 500;
 }
 
+.wcag-link {
+    color: var(--info);
+    text-decoration: none;
+    font-weight: 600;
+    border-bottom: 1px dotted var(--info);
+    transition: color 0.15s, border-color 0.15s;
+}
+
+.wcag-link:hover {
+    color: var(--accent);
+    border-bottom-color: var(--accent);
+}
+
 .issue-recommendation {
     background: var(--success-bg);
     padding: 10px 12px;

js/results.js

@@ -143,7 +143,7 @@ function createIssueCard(issue, issueNumber, globalIndex) {
             </div>
         </div>
         <div class="issue-description">${issue.description}</div>
-        ${issue.wcag_criterion ? `<div class="issue-meta"><span>WCAG ${issue.wcag_criterion}</span></div>` : ''}
+        ${issue.wcag_criterion ? `<div class="issue-meta">${wcagCriterionLinks(issue.wcag_criterion)}</div>` : ''}
         ${issue.recommendation ? `<div class="issue-recommendation"><strong>Tip:</strong> ${issue.recommendation}</div>` : ''}
     </div>`;
 }

js/utils.js

@@ -59,6 +59,80 @@ function getSeverityIcon(severity) {
     return map[severity] || '\u2022';
 }
 
+/* WCAG 2.1 criterion → Understanding page slug */
+const WCAG_SLUGS = {
+    '1.1.1': 'non-text-content',
+    '1.2.1': 'audio-only-and-video-only-prerecorded',
+    '1.2.2': 'captions-prerecorded',
+    '1.2.3': 'audio-description-or-media-alternative-prerecorded',
+    '1.2.4': 'captions-live',
+    '1.2.5': 'audio-description-prerecorded',
+    '1.3.1': 'info-and-relationships',
+    '1.3.2': 'meaningful-sequence',
+    '1.3.3': 'sensory-characteristics',
+    '1.3.4': 'orientation',
+    '1.3.5': 'identify-input-purpose',
+    '1.4.1': 'use-of-color',
+    '1.4.2': 'audio-control',
+    '1.4.3': 'contrast-minimum',
+    '1.4.4': 'resize-text',
+    '1.4.5': 'images-of-text',
+    '1.4.6': 'contrast-enhanced',
+    '1.4.10': 'reflow',
+    '1.4.11': 'non-text-contrast',
+    '1.4.12': 'text-spacing',
+    '1.4.13': 'content-on-hover-or-focus',
+    '2.1.1': 'keyboard',
+    '2.1.2': 'no-keyboard-trap',
+    '2.2.1': 'timing-adjustable',
+    '2.2.2': 'pause-stop-hide',
+    '2.3.1': 'three-flashes-or-below-threshold',
+    '2.4.1': 'bypass-blocks',
+    '2.4.2': 'page-titled',
+    '2.4.3': 'focus-order',
+    '2.4.4': 'link-purpose-in-context',
+    '2.4.5': 'multiple-ways',
+    '2.4.6': 'headings-and-labels',
+    '2.4.7': 'focus-visible',
+    '2.5.3': 'label-in-name',
+    '3.1.1': 'language-of-page',
+    '3.1.2': 'language-of-parts',
+    '3.1.5': 'reading-level',
+    '3.2.1': 'on-focus',
+    '3.2.2': 'on-input',
+    '3.2.3': 'consistent-navigation',
+    '3.2.4': 'consistent-identification',
+    '3.3.1': 'error-identification',
+    '3.3.2': 'labels-or-instructions',
+    '3.3.3': 'error-suggestion',
+    '3.3.4': 'error-prevention-legal-financial-data',
+    '4.1.1': 'parsing',
+    '4.1.2': 'name-role-value',
+    '4.1.3': 'status-messages',
+};
+
+/**
+ * Returns an HTML string of clickable WCAG criterion links.
+ * Handles comma-separated criteria (e.g. "1.3.1, 4.1.2") and "PDF/UA".
+ */
+function wcagCriterionLinks(criterion) {
+    if (!criterion) return '';
+
+    if (criterion.trim().toUpperCase() === 'PDF/UA') {
+        return '<a href="https://www.pdfa.org/pdfua/" target="_blank" rel="noopener" class="wcag-link">PDF/UA</a>';
+    }
+
+    return criterion.split(',').map(part => {
+        const num = part.trim();
+        const slug = WCAG_SLUGS[num];
+        if (slug) {
+            const url = `https://www.w3.org/WAI/WCAG21/Understanding/${slug}`;
+            return `<a href="${url}" target="_blank" rel="noopener" class="wcag-link">WCAG ${num}</a>`;
+        }
+        return `WCAG ${num}`;
+    }).join(', ');
+}
+
 function escapeAttr(str) {
     return String(str).replace(/\\/g, '\\\\').replace(/'/g, "\\'").replace(/"/g, '&quot;');
 }