This required a buncha fixes to how SASS scoping works! Needed to add a bunch of imports for stuff that previously would get read from the global scope by being imported *after* the constants and mixins etc.
There's clearly a lot of refactor opportunity here, but I'm not gonna worry about it!!
I wasn't sure what we were actually using it for, turns out it was mostly polyfills for CSS features that are very standard now!
I didn't audit these changes very carefully tbqh because they seemed pretty simple? Fingers crossed!
