- Add CSS Colors, Typography, Advanced Selectors, and Grid modules
- Remove deprecated HTML Marquee module from all languages
- Remove redundant div & span lesson from HTML Block & Inline
- Move SVG module from HTML to CSS section
- Enhance first lessons with comprehensive explanations:
- Flexbox: historical context, axes concept
- Colors: named colors, background-color explained
- Grid: comparison to Flexbox, key properties
- Swap header logo highlight (CRISPIES instead of CODE)
- Use English fallbacks for new modules in non-EN languages
- Fix test to include 'playground' mode
New path: 19 modules (~78 lessons) vs previous 16 modules (62 lessons)
🤖 Generated with [Claude Code](https://claude.com/claude-code)
- Fixed validation in welcome lesson (Hello World instead of Hello)
- Replaced 'quoted text' with <code>quoted text</code> in all task descriptions
- Added syntax examples to Transitions and Keyframes lessons
- Updated all language versions (en, de, pl, es, ar, uk)
- Create lesson directories and copy English lessons as templates
- Add full UI translations for pl, es, ar, uk languages
- Update lessons.js with module stores for all new languages
- Implement language cycling (en → de → pl → es → ar → uk → en)
- Fix playground mode detection (lesson.mode takes precedence)
