Add tailwind 4

app/app.css

@@ -0,0 +1 @@
+@import "tailwindcss";

app/app.ts

@@ -2,6 +2,7 @@ import Application from '@ember/application';
 import Resolver from 'ember-resolver';
 import loadInitializers from 'ember-load-initializers';
 import config from 'lofi/config/environment';
+import 'lofi/app.css';
 
 export default class App extends Application {
   modulePrefix = config.modulePrefix;

app/templates/application.hbs

@@ -3,5 +3,8 @@
 {{outlet}}
 
 {{! The following component displays Ember's default welcome message. }}
-<WelcomePage />
-{{! Feel free to remove this! }}
+{{! Feel free to remove this! }}
+
+<h1 class="text-3xl font-bold underline">
+  Hello world!
+</h1>

ember-cli-build.js

@@ -22,5 +22,17 @@ module.exports = function (defaults) {
         package: 'qunit',
       },
     ],
+    packagerOptions: {
+      webpackConfig: {
+        module: {
+          rules: [
+            {
+              test: /\.css$/i,
+              use: ['postcss-loader'],
+            },
+          ],
+        },
+      },
+    },
   });
 };