Clearly describe the bug

::-moz-focus-inner is treated as a pseudo-class, not a pseudo-element, and so can cause false positives in no-descending-specificity.

Which rule, if any, is the bug related to?

no-descending-specificity

What code is needed to reproduce the bug?

a::-moz-focus-inner {}
a 

To reproduce:

$ npm pack styled-jsx@3.2.4
npm notice
npm notice 📦  styled-jsx@3.2.4
npm notice === Tarball Contents ===
npm notice 6.1kB  dist/.DS_Store
npm notice 599B   dist/_constants.js
npm notice 22.3kB dist/_utils.js
npm notice 8.2kB  dist/babel-external.js
npm notice 46B    babel-test.js
npm notice 753B   dist/babel-test.js
npm notice 41B    babel.js
npm notice 10.4k

Can we have numeric values allowed for tokens like fontWeights, zIndices, linHeights`, etc?
Example: https://codesandbox.io/s/stitches-ts-issue-forked-voh43?file=/src/stitches.config.ts

Recently @devrnt opened up a PR to improve the setup with a theme(#189) and I realised that it'll be awesome to have that section expanded for each case.