- Added theme variables for light and dark modes in viewer-template.html.
- Created a custom hook `useTheme` to manage theme preferences and resolve the current theme based on user selection or system settings.
- Introduced `ThemeToggle` component to allow users to switch between themes.
- Updated `Header` component to include the `ThemeToggle` and pass theme preference and change handler.
- Modified `App` component to integrate theme management and pass relevant props to child components.
Alex Newman
f46b5b452f
