Make purgecss work only on build

app/scripts/components/common/banner/index.tsx

@@ -50,7 +50,7 @@ export default function Banner({appTitle, expires, url, text, type = infoTypeFla
           </USWDSBanner>
           <div className='position-absolute top-0 right-0 margin-right-3 height-full display-flex'>
               <button 
-              className='usa-button usa-button--secondary usa-button--unstyled'
+              className='usa-button usa-button--unstyled'
               type='button'
               aria-label='Close Banner'
               onClick={onClose}

app/scripts/main.tsx

@@ -44,7 +44,6 @@ const Sandbox = lazy(() => import('$components/sandbox'));
 
 const UserPagesComponent = lazy(() => import('$components/user-pages'));
 
-
 // Contexts
 import { ReactQueryProvider } from '$context/react-query';
 import {

postcss.config.js

@@ -1,18 +1,19 @@
+let plugins = [require('autoprefixer'), require('postcss-import')];
+const purge = require('@fullhuman/postcss-purgecss')({
+  content: [
+    './app/**/*.{js,jsx,ts,tsx}',
+    '@trussworks/react-uswds/lib/index.css'
+  ],
+  safelist: {
+    deep: [/usa-banner$/],
+    greedy: [/^usa-banner/]
+  }
+});
+
+if (process.env.NODE_ENV !== 'development') plugins = [...plugins, purge];
+
 module.exports = {
   syntax: 'postcss-scss',
   parser: 'postcss-safe-parser',
-  plugins: [
-    require('autoprefixer'),
-    require('postcss-import'),
-    require('@fullhuman/postcss-purgecss')({
-      content: [
-        './app/**/*.{js,jsx,ts,tsx}',
-        '@trussworks/react-uswds/lib/index.css'
-      ],
-      safelist: {
-        deep: [/usa-banner$/],
-        greedy: [/^usa-banner/]
-      }
-    })
-  ]
+  plugins
 };