Prevent HTML elements like <details>, <option>, <form> from being
rendered as actual elements in hint messages by properly escaping
them with < > and wrapping in <kbd> tags.
Flexbox and Box Model lessons:
- Use explicit task instructions with selector AND property
- Include selector in codePrefix for better context
- Replace hex colors with named CSS colors (steelblue, coral, etc.)
- Simplify values (2px instead of 0.125rem, 1rem instead of 1.25rem)
- Remove redundant contains validations
- Wrap code examples in <code> tags for proper styling
- Add 5 CSS modules to lessons.js config (EN)
- Create German translations for all 5 CSS modules
- Add CSS modules to lessons.de.js config
- Fix test to use toBeGreaterThanOrEqual for module count
- 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
- Remove presentational classes (.form-group, .required, .hint, .checkbox-group)
- Replace <span class="required">*</span> with plain * in label text
- Replace <div class="hint"> with semantic <small> element
- Simplify checkbox markup to use native label wrapping pattern
- Update previewBaseCSS to style semantic elements directly
- Add code quality standards to CLAUDE.md emphasizing WCAG compliance and native HTML
- Add German HTML entry point (index.de.html)
- Add German app.js with translated UI strings (app.de.js)
- Add German lesson config (lessons.de.js)
- Add German translations of all 6 lesson modules:
- HTML Elements: Block vs Inline
- HTML Forms: Basic Inputs
- HTML Forms: Validation
- CSS: Basic Selectors
- CSS: Advanced Selectors
- Tailwind: Basics
All IDs, variable names, and code examples remain in English.
Only user-facing text has been translated to German.
