`.td-box--white` should be dark-mode compatible

- Context: 
  - https://github.com/open-telemetry/opentelemetry.io/issues/4023#issuecomment-2076383659
  - https://github.com/open-telemetry/opentelemetry.io/issues/4023#issuecomment-2076587922
- Contributes to #331 

### Tasks

- [x] #1966 
- [x] #1968