### Bug description

When using revealjs mode with Quarto if you set a slide to a dark background and include a footer the footer colour does not adjust to the dark background.

The footer appears to be moved outside of the slide section where revealjs sets `has-dark-background` class so it isn't possible to just apply scss logic within `src/resources/formats/revealjs/quarto.scss`.

## Steps to reproduce

Using the [attached file](https://github.com/quarto-dev/quarto-cli/files/10544325/footer-colour.txt) do the following:

```bash
$ mv footer-colour.txt footer-colour.qmd

$ quarto preview footer-colour.qmd
```

## OS Information

I've tested this on the most recent nightly release and still have this issue.

Running on macOS Ventura 13.1.


### Checklist

- [X] Please include a minimal, fully reproducible example in a single .qmd file? Please provide the whole file rather than the snippet you believe is causing the issue.
- [X] Please [format your issue](https://quarto.org/bug-reports.html#formatting-make-githubs-markdown-work-for-us) so it is easier for us to read the bug report.
- [X] Please document the RStudio IDE version you're running (if applicable), by providing the value displayed in the "About RStudio" main menu dialog?
- [X] Please document the operating system you're running. If on Linux, please provide the specific distribution.
cderv
2023-01-31T08:33:17Z
Sparrow0hawk
bug
v1.4
open
Footer text colour doesn't change with darker background colours
https://github.com/quarto-dev/quarto-cli/issues/4156