PostCSS syntax for parsing Markdown
First thing's first, install the module:
npm install postcss-markdown --save-devIf you want support SCSS/SASS/LESS/SugarSS syntax, you need to install the corresponding module.
- SCSS: postcss-scss
- SASS: postcss-sass
- LESS: postcss-less
- SugarSS: sugarss
- Stylus: postcss-styl
This package is written in ESM and requires Node.js ^22.12 || >=24. CommonJS consumers can still load it with require("postcss-markdown") on these Node.js versions (via require(esm)).
import postcss from "postcss";
import postcssMarkdown from "postcss-markdown";
import postcssScss from "postcss-scss";
import postcssLess from "postcss-less";
import postcssSafeParser from "postcss-safe-parser";
import autoprefixer from "autoprefixer";
const syntax = postcssMarkdown({
// Enable support for HTML (default: true)
htmlInMd: true,
// syntax for parse scss (non-required options)
scss: postcssScss,
// syntax for parse less (non-required options)
less: postcssLess,
// syntax for parse css blocks (non-required options)
css: postcssSafeParser,
});
postcss([autoprefixer])
.process(source, { syntax: syntax })
.then(function (result) {
// An alias for the result.css property. Use it with syntaxes that generate non-CSS output.
result.content;
});input:
# title
```css
::placeholder {
color: gray;
}
```
output:
# title
```css
::-moz-placeholder {
color: gray;
}
:-ms-input-placeholder {
color: gray;
}
::placeholder {
color: gray;
}
```
If you want support SCSS/SASS/LESS/SugarSS syntax, you need to install these module:
- SCSS: postcss-scss
- SASS: postcss-sass
- LESS: postcss-less
- SugarSS: sugarss
- Stylus: postcss-styl
import { createRequire } from "module";
import postcssMarkdown from "postcss-markdown";
import postcssSass from "postcss-sass";
import sugarss from "sugarss";
import postcssCustomSyntax from "postcss-custom-syntax";
const options = {
rules: [
{
// custom language
test: /^postcss$/i,
lang: "scss",
},
{
// custom language
test: /^customcss$/i,
lang: "custom",
},
],
// custom parser for CSS (using `postcss-safe-parser`)
css: "postcss-safe-parser",
// custom parser for SASS (PostCSS-compatible syntax.)
sass: postcssSass,
// custom parser for SCSS (by module name)
scss: "postcss-scss",
// custom parser for LESS (by module path)
less: createRequire(import.meta.url).resolve("postcss-less"),
// custom parser for SugarSS
sugarss: sugarss,
// custom parser for custom language
custom: postcssCustomSyntax,
};
const syntax = postcssMarkdown(options);PostCSS can be temporarily turned off by using special comments in your Markdown. For example:
<!-- postcss-ignore -->
```css
a {
color: red;
}
```
The main use case of this plugin is to apply linting with Stylelint to CSS (and CSS-like) code blocks in markdown file.
You can use it by configuring your stylelint config as follows:
{
"overrides": [
{
"files": ["*.md", "**/*.md"],
"customSyntax": "postcss-markdown"
}
]
}Use the stylelint.vscode-stylelint extension that Stylelint provides officially.
You have to configure the stylelint.validate option of the extension to check .md files, because the extension does not check the *.md file by default.
Example .vscode/settings.json:
{ "stylelint.validate": [ ..., // ↓ Add "markdown" language. "markdown" ]