Use CSS variables to handle theming

[rbreslow]

Right now, we have methods on the JS instance to set individual style properties like font family, size, etc. It'd be nice to roll this up into one setTheme(data) method that takes a JSON object and then updates CSS variables, rather than iterating over elements and setting what are essentially inline styles.

See:

• https://codyhouse.co/blog/post/dark-light-switch-css-javascript
• https://css-tricks.com/updating-a-css-variable-with-javascript/

[rbreslow]

It'd be nice to have some prebaked themes like:

And then have an unfurlable DProperties element for doing your own customization:

You could theme the chatbox and then copy your generated JSON theme and share with other folks / enforce it via a policy.