This is available if you use a pre-release of Bedrock 1.34, which is on the development branch.

To try this, grab a fresh Bedrock install:

npx degit usebedrock/bedrock#develop my-bedrock-project

Now, go into the project and the code. First you will want to set your CSS compiler to PostCSS in the bedrock.config.js file:

css: {
  compiler: 'postcss',
    minify: false,
    purge: false
}

The default CSS compiler is scss.

Now, install these dependencies as devDependencies:

npm i -D tailwindcss
npm i -D @tailwindcss/typography

The typography plugin is optional but I like it so I put it here as a default. Add a Tailwind config file:

touch tailwind.config.js

Add contents:

// tailwind.config.js

module.exports = {
  purge: [],
  darkMode: false, // or 'media' or 'class'
  theme: {
    extend: {},
  },
  variants: {
    extend: {},
  },
  plugins: [
    require('@tailwindcss/typography'),
  ],
  separator: '_',
}

Note that the _ separator is needed for Pug. Any Tailwind example you copy paste will need to have the : that is used to for things like hover or dark mode be changed into _ (read docs).

Then change the default postcss.config.js in Bedrock (none found? Check this post) from:

const atImport = require('postcss-import');
const autoprefixer = require('autoprefixer');

module.exports = [atImport, autoprefixer];

To

const atImport = require('postcss-import');
const tailwindcss = require('tailwindcss');
const autoprefixer = require('autoprefixer');

module.exports = [atImport, tailwindcss, autoprefixer];

You can use this mechanism to add any PostCSS plugin you like really. Now test if it works by going to content/postcss/main.css and loading Tailwind by adding these lines:

@tailwind base;
@tailwind components;
@tailwind utilities;

Now you can look at /tmp/main.css (tmp is where files are written to temporarily in dev mode) and be shocked at the 4Mb CSS file.

You will now want to enable CSS purging in the bedrock.config.js. Change

  css: {
    compiler: 'postcss',
    minify: false,
    purge: false
  },

to

  css: {
    compiler: 'postcss',
    minify: false,
    purge: true
  },

Restart bedrock (because you made config changes). Now look at the output again. In the tmp folder you will the same 4Mb CSS file. But if you run npm run build, you will see a much smaller (+-11kb on the default Bedrock install) in the dist folder.

This is because we purge the CSS using the HTML output. This can be used to have a final version of your CSS that has a reasonable file size.

Note that the purge feature is available regardless of using PostCSS. So you can also purge your SCSS output now. As noted in some Github issues, Bedrock might as well be used to make production sites if we can put in just a few more changes (like minifying CSS and JS).

As some may know I am not a big fan of Tailwind, but it has to be said that because of Tailwind I now implemented PostCSS and PurgeCSS support in Bedrock, which I’m sure are good features on their own.

Yeehaw!