Black & White compact themes with verbatim headers.

[peter-lyons-kehl]

Dear Hakim,

Thank you for Reveal.js, and for your continuous support and improvements.

This pull request adds two themes: black_contrast_compact_verbatim_headers.scss and white_contrast_compact_verbatim_headers.scss. They're based on your black.scss and white.scss, with modifications

• headers are verbatim (rather than in CAPITAL CASE) - useful when the words/terms are in CamelCase or mixed;
• compact (less spacing) - using the screen more;
• high contrast (pure black on pure white, and vice-versa).

This would help my existing presentation (https://peter-kehl.github.io/no_std_rust_libs = https://github.com/peter-kehl/no_std_rust_libs) and 18+ more presentations to come (https://github.com/peter-kehl/no_std_patterns).

Could there be a better way to organize/centralize the code shared between black.scss and black_contrast_compact_verbatim_headers.scss (and between white.scss and white_contrast_compact_verbatim_headers.scss), please do as you see fit.

Thank you in advance either way. Related to #3312.

[hakimel]

Thanks for taking the time to create this, Peter!

I like the idea of a max contrast theme and have merge this and renamed them to black-contrast/white-contrast. However I undid the changes you made to font size and text transform because I don't think it scale very well to provide individual themes for smaller variations like that. It was hard to think of a good reason to have those properties vary between the black vs black-contrast themes when in all other aspects they are so similar.

To achieve the same style as in your original theme, you can use the black/white-contrast themes and append the following style tag anywhere on your page:

<style>
  :root {
    --r-main-font-size: 25px;
    --r-heading-font-weight: 450;
    --r-heading-text-transform: none;
  }
</style>