postcss.config.js

// Configure purgecss plugin
const purgecss = require("@fullhuman/postcss-purgecss")({
  // Specify the paths to all of the template files in your project
  content: [
    "./templates/**/*.html",
    // './src/**/*.jsx',
    // './src/**/*.js'
  ],

  // This is the function used to extract class names from your templates
  defaultExtractor: (content) => {
    // Capture as liberally as possible, including things like `h-(screen-1.5)`
    const broadMatches = content.match(/[^<>"'`\s]*[^<>"'`\s:]/g) || [];

    // Capture classes within other delimiters like .block(class="w-1/2") in Pug
    const innerMatches = content.match(/[^<>"'`\s.()]*[^<>"'`\s.():]/g) || [];

    return broadMatches.concat(innerMatches);
  },
});

// Export all plugins our postcss should use
module.exports = {
  plugins: [
    require("tailwindcss"),
    require("autoprefixer"),

    ...(process.env.NODE_ENV === "production"
      ? [
          purgecss,
          require("cssnano")({
            preset: "default",
          }),
        ]
      : []),
  ],
};