use cssnano instead of clean-css for the minified CDN build

Author: RobinMalfait

package-lock.json

@@ -2,6 +2,7 @@ import fs from 'fs'
 import postcss from 'postcss'
 import tailwind from '..'
 import CleanCSS from 'clean-css'
+import cssnano from 'cssnano'
 
 function buildDistFile(filename, config = {}, outFilename = filename) {
   return new Promise((resolve, reject) => {
@@ -20,8 +21,13 @@ function buildDistFile(filename, config = {}, outFilename = filename) {
           return result
         })
         .then((result) => {
-          const minified = new CleanCSS().minify(result.css)
-          fs.writeFileSync(`./dist/${outFilename}.min.css`, minified.styles)
+          return postcss([cssnano]).process(result.css, {
+            from: `./${filename}.css`,
+            to: `./dist/${outFilename}.min.css`,
+          })
+        })
+        .then((result) => {
+          fs.writeFileSync(`./dist/${outFilename}.min.css`, result.css)
         })
         .then(resolve)
         .catch((error) => {