- Add skip-to-content link for keyboard users
- Convert module headers and lesson items from divs to buttons
- Add ARIA attributes (aria-expanded, aria-controls, aria-label)
- Add focus return to trigger element when closing sidebar
- Shift main content when sidebar is open using CSS :has()
- Add code element styling in instruction boxes
- Fix renderLesson to handle null inputEl (CodeMirror replaces textarea)
- Fix renderExpectedPreview to use 'solution' property instead of 'solutionCode'
- These fixes restore level indicator, expected preview, and auto-run functionality
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
- Add HTML mode support with new validation types (element_exists,
element_count, attribute_value, element_text, parent_child, sibling)
- Create 3 HTML lesson modules: Elements, Forms Basic, Forms Validation
- Implement side-by-side preview comparison (Your Output vs Expected)
- Add merge animation with "Perfect Match!" overlay on validation success
- Render expected output from solutionCode field in lesson JSON
- Update schema to support HTML mode and solutionCode
- Reorder modules: HTML first, then CSS, then Tailwind
- Update tests for new functionality
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
