- Isolate PagedJS in iframe to avoid DOM/CSS conflicts
- Add EditorPanel for global CSS controls
- Add StylesheetViewer with highlight.js syntax highlighting
- Add ElementPopup for element-specific CSS editing
- CSS modifications update preview reactively
- Support px/rem/em units
🤖 Generated with [Claude Code](https://claude.com/claude-code)
Co-Authored-By: Claude <noreply@anthropic.com>
