- 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)
- Add contact section to help dialog with librete.ch, GitHub, Gitea, LinkedIn links
- Add HTML/CSS prefixes to English module titles for consistency with German
- Add CSS transitions for smooth lesson switching
- Add transitioning class to prevent content flash during lesson changes
- Add <kbd> tags to CSS property values and selectors in task descriptions
- Add solution code to all lessons for better guidance
- Improve animation contrast in transitions lesson (black/white instead
of similar purples, dramatic color changes for visibility)
- Simplify validation messages with kbd formatting