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
