- Add WCAG-compliant luminance calculation to Color extension - Add contrastingTextColor method to MoodTints for automatic black/white text - Update 12+ entry styles to use dynamic text colors instead of hardcoded white - Change theme preview sheet to full screen presentation Text now automatically switches between black and white based on background brightness, fixing readability issues on light mood colors like yellow (Good). 🤖 Generated with [Claude Code](https://claude.com/claude-code) Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>