I've replaced all `"$something$something"` CSS variables with
`variables.something.something`. Now we have autocomplete and
type-safety: if a variable is removed or renamed w/o fixing the usage
the build will fail.
This will allow designers to change design tokens and either make sure
nothing is broken or if something is broken we'll know exactly what and
it will be easy to fix.
Discussed here:
https://discord.com/channels/955905230107738152/1061992022665334837
