Add cssnano and purgecss

package.json

@@ -1,6 +1,8 @@
 {
   "dependencies": {
+    "@fullhuman/postcss-purgecss": "^2.1.0",
     "autoprefixer": "^9.7.5",
+    "cssnano": "^4.1.10",
     "tailwindcss": "^1.2.0",
     "watch": "^1.0.2"
   },

postcss.config.js

@@ -1,5 +1,16 @@
+const purgecss = require('@fullhuman/postcss-purgecss')
+const cssnano = require('cssnano')
+
 module.exports = {
   plugins: [
     require('tailwindcss'),
+    require('autoprefixer'),
+    cssnano({
+      preset: 'default'
+    }),
+    purgecss({
+      content: ['./src/*.htm'],
+      defaultExtractor: content => content.match(/[\w-/:]+(?<!:)/g) || []
+    })
   ]
 }