junk: Scoped button CSS variables

[creido-welly]

Context

Proof of concept for scoping of CSS variables i.e. not within a :root { } block.

The scoping demonstrated in this file provides very succinct and I would argue more readable code and results in far fewer variables. This works well when being consumed as a package. Further discovery work should be done to see how this could be optimised for theming.

Caveat

Scoped variables do not work well with CSS variable compiling using a Postcss plugin such as postcss-css-variables or postcss-custom-properties.

See below a summary of how CSS properties compile to hex values:

	Works with :root variables	Works with scoped variables
Main app	Yes	Yes
Package	Yes	Not reliable