New Twiddle

controller.application\.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName: 'Ember Twiddle Test'
});

styles.application\.block\.css

:scope {
  background: blue;
}

.title {
  color: yellow;
}

.title[state|active] {
  color: blue;
}

templates.application.hbs

<div>
  <h1 class="title" state:active>Welcome to {{appName}}</h1>
  <br>
  <br>
  {{outlet}}
  <br>
  <br>
</div>

twiddle.json

{
  "version": "0.15.1",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.js",
    "ember": "3.4.3",
    "ember-template-compiler": "3.4.3",
    "ember-testing": "3.4.3"
  },
  "addons": {
    "ember-data": "3.4.2",
    "@css-blocks/core": "0.23.2"
  }
}