- Fix switch component thumb appearing all white when ON
- Add --cal-brand-accent CSS variable definitions for light and dark modes
- Ensures proper contrast: white accent on dark bg, black accent on light bg
- Resolves UI issue on /getting-started/connected-calendar and /getting-started/setup-availability pages
Fixes switch components using bg-brand-accent class that maps to var(--cal-brand-accent,white)
When CSS variable was undefined, it defaulted to white causing invisible thumbs.
Co-authored-by: Kartik Saini <41051387+kart1ka@users.noreply.github.com>