Status: Accepted Date: 2026-04-19
The tutorial site may use a dark theme. Diagrams exported as PNGs with transparent backgrounds would have dark arrow strokes and text labels that become invisible on dark page backgrounds.
Every diagram includes a white (#FFFFFF) rounded rectangle with a
neutral border (#D3D1C7) behind all content. PNGs are exported with
transparent background — the card provides the contrast.
- White background on PNG export: Always readable but clashes with dark themes (white rectangle on dark page)
- Two versions (light + dark): Correct but doubles maintenance
- Transparent with no card: Breaks on dark backgrounds
- All draw.io files must include a
bg-cardelement as the first child - The card must be sized to contain all diagram content with padding
- Works on both light and dark page backgrounds