this version will run with npm start, but when attempting to run the built version behind nginx, it appears to have issues
PostCSS Focus Visible 
PostCSS Focus Visible lets you use the :focus-visible pseudo-class in
CSS, following the Selectors Level 4 specification.
It is the companion to the focus-visible polyfill.
:focus:not(:focus-visible) {
outline: none;
}
/* becomes */
:focus:not(.focus-visible) {
outline: none;
}
:focus:not(:focus-visible) {
outline: none;
}
PostCSS Focus Visible duplicates rules using the :focus-visible pseudo-class
with a .focus-visible class selector, the same selector used by the
focus-visible polyfill. This replacement selector can be changed using the
replaceWith option. Also, the preservation of the original :focus-visible
rule can be disabled using the preserve option.
Usage
Add PostCSS Focus Visible to your project:
npm install postcss-focus-visible --save-dev
Use PostCSS Focus Visible to process your CSS:
const postcssFocusVisible = require('postcss-focus-visible');
postcssFocusVisible.process(YOUR_CSS /*, processOptions, pluginOptions */);
Or use it as a PostCSS plugin:
const postcss = require('postcss');
const postcssFocusVisible = require('postcss-focus-visible');
postcss([
postcssFocusVisible(/* pluginOptions */)
]).process(YOUR_CSS /*, processOptions */);
PostCSS Focus Visible runs in all Node environments, with special instructions for:
| Node | PostCSS CLI | Webpack | Create React App | Gulp | Grunt |
|---|
Options
preserve
The preserve option defines whether the original selector should remain. By
default, the original selector is preserved.
focusVisible({ preserve: false });
:focus:not(:focus-visible) {
outline: none;
}
/* becomes */
:focus:not(.focus-visible) {
outline: none;
}
replaceWith
The replaceWith option defines the selector to replace :focus-visible. By
default, the replacement selector is .focus-visible.
focusVisible({ replaceWith: '[focus-visible]' });
:focus:not(:focus-visible) {
outline: none;
}
/* becomes */
:focus:not([focus-visible]) {
outline: none;
}
:focus:not(:focus-visible) {
outline: none;
}