- 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
- Import both EN and DE lesson files in lessons.js
- loadModules() now accepts language parameter
- toggleLanguage() reloads lessons in new language
- initializeModules() uses current language from i18n
- Preserves user position when switching languages
- Create i18n.js module with EN/DE translations
- Add data-i18n attributes to index.html for dynamic text
- Update renderer.js to use translation functions
- Language switcher button replaces link to German page
- Stores preference in localStorage, detects browser language
Native dialog elements don't close on backdrop click by default.
Added click handlers that check if click target is the dialog itself
(not its children) to enable this expected UX behavior.
Clean up lesson files by removing useless HTML comment placeholders
from initialCode fields. Users now start with a clean editor instead
of seeing instructional comments they need to delete.
Document learnings for creating effective lessons:
- Clear task instructions with selector and property
- Use codePrefix for context
- Simple, human-friendly values
- Named CSS colors for engagement
- Focused validations
- Semantic HTML in examples
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
- Style code elements in task instructions with white alpha background
- Style code elements in lesson descriptions and hints
- Add skip-link CSS for keyboard navigation
- Add sidebar shift animation when drawer is open
- Add focus styles for sidebar navigation items
- 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
- 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
- Add module title pill above lesson title showing current category
- Enable next/prev buttons to cross module boundaries
- Automatically advance to next module when completing last lesson
- Go to last lesson of previous module when navigating back
- 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
- Update overlay text: "Perfect Match!" → "CRISPY! ٩(◕‿◕)۶"
- Update success hint in English and German versions
- Fun branding touch matching the app name
- Convert help and reset modals to native <dialog> elements
- Content is now in HTML, not dynamically generated via JS
- Use dialog.showModal() and dialog.close() native API
- Dialog handles Escape key natively for closing
- Fix list indentation in help dialog with proper padding
- Add styled kbd elements for keyboard shortcuts
- Separate dialogs for help and reset confirmation
- Apply same changes to German version
Benefits:
- Better accessibility (native focus trapping, escape handling)
- Simpler JavaScript (no DOM manipulation for content)
- Content visible in HTML source for easier editing
- Native backdrop styling via ::backdrop
- Add language toggle button in header (EN/DE)
- Link directly to the other language version
- Style consistent with existing header buttons
- Accessible with proper aria-labels
- 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.
- Add history extension to CodeMirror for undo/redo support
- Ctrl+Z for undo, Ctrl+Shift+Z for redo now work
- Add toolbar buttons: ↶ Undo, ↷ Redo, ⟲ Reset
- Reset button restores editor to initial lesson code
- Add .btn-icon and .editor-tools CSS styles
Update task instructions to explicitly specify all content that appears
in the solution, so students can complete lessons without guessing:
- semantic-containers: specify "My Website", "Welcome to my site!", "Copyright 2025"
- form-structure: specify label text "Name:" and attribute values
- input-types: specify label texts "Email:" and "Password:"
- input-constraints: specify placeholder text "Enter password"
- Replace custom highlight styles with @codemirror/theme-one-dark
- Cleaner implementation with official CodeMirror theme
- Keep custom font and padding overrides
- Replace textarea with CodeMirror 6 for syntax highlighting
- Add Emmet abbreviation expansion (Tab to expand)
- Support HTML and CSS language modes with autocomplete
- Add dark theme matching app design
- Tab indentation with Shift-Tab for outdent
- Update help modal with Emmet shortcuts
- Implement 50/50 split layout (left: instructions + editor, right: preview)
- Replace always-visible sidebar with slide-out drawer menu
- Move footer, progress, and settings into sidebar
- Add toggleable expected result overlay (hidden by default)
- Create new hint system with step progress indicators
- Add ghost button styles for modal and text button for sidebar reset
- Fix HTML lesson task instruction and typo ("important" not "importing")
- Add padding to preview frames to prevent corner clipping
- Optimize layout for iPadOS and tablet devices
- 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
