Restyle the Slides

## Do you have an eye for design?
Help us improve the look of the slide deck.
If you need help, check out the Appendix in the training manual.

Start by locating the slide deck in the repository and read the Appendix in the training manual for context. The issue does not identify files, specific design problems, or acceptance criteria, so clarify the desired visual changes before working. Done means the deck's look has been improved and the updated slides render consistently.

Written by the indexing model from the issue text.