csstools
PostCSS Initial 
npm install @csstools/postcss-initial --save-dev
PostCSS Initial fallback the initial keyword following the CSS Cascade 4 Specification.
.foo {
border: initial;
}
/* becomes */
.foo {
border: medium none currentcolor;
border: initial;
}See prior work by maximkoretskiy here postcss-initial To ensure long term maintenance and to provide the needed features this plugin was recreated based on maximkoretskiy's work.
Usage
Add PostCSS Initial to your project:
npm install postcss @csstools/postcss-initial --save-devUse it as a PostCSS plugin:
const postcss = require('postcss');
const postcssInitial = require('@csstools/postcss-initial');
postcss([
postcssInitial(/* pluginOptions */)
]).process(YOUR_CSS /*, processOptions */);Options
preserve
The preserve option determines whether the original notation
is preserved. By default, it is preserved.
postcssInitial({ preserve: false }).foo {
border: initial;
}
/* becomes */
.foo {
border: medium none currentcolor;
}