When I run `bin/deploy:precompile` on the previous version, I get an
error from libsass that `vw` and `vh` are incompatible units. I don't
get this error in development, only when compiling for production.
My inference is:
1. For the production build, Sass is trying to preprocess even non-SASS
files, maybe to help minify them?
2. In Sass, their `min()` existed before CSS's `min()`, so it's
treating it Like That, and returning a reasonable-in-some-cases-but-
not-here error that `min(100vw, 100vh)` can't be *precomputed*.
Anyway, wrapping it in `calc()` isn't a *problem*, and helps the Sass
compiler not try to precompute it, so. Okay!
https://github.com/sass/node-sass/issues/2815#issuecomment-575926329