postcss.config.js

module.exports = {
  plugins: [
    "postcss-flexbugs-fixes",
    [
      "postcss-preset-env",
      {
        autoprefixer: {
          flexbox: "no-2009",
        },
        stage: 3,
        features: {
          "custom-properties": false,
        },
      },
    ],
    [
      "@fullhuman/postcss-purgecss",
      {
        content: [
          "./pages/**/*.{js,jsx,ts,tsx}",
          "./components/**/*.{js,jsx,ts,tsx}",
        ],
        /* it's important that the first character class here includes a
         * backslash, because sass generates css selector names that include a
         * backslash like: ".mobile-lg\:grid-col", which we need to make sure
         * that purge parses as a single selector. purgecess does not propely
         * parse CSS, so we have to be kind of loose here to get it to work. */
        defaultExtractor: (content) => content.match(/[\w-/\\:]+(?<!:)/g) || [],
        safelist: {
          standard: ["html", "body"],
          greedy: [],
        },
      },
    ],
  ],
};