- 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)
- Shorten German module titles with consistent HTML/CSS prefixes
- Add .completion-badge styling for the lesson title completion badge
- Make sidebar lessons section fill available height on desktop
- Improve flexbox lesson descriptions with more context
- Wrap HTML element names in <kbd> tags in all validation messages
- Apply consistent formatting to both English and German lessons
- Make hints clearer about which elements/attributes to use
- Fix mobile editor layout overflow issue
