New Twiddle

controllers.application.js

import Ember from 'ember';

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

styles.app.css

body {
  margin: 12px 16px;
  font-family: 'Helvetica Neue', Helvetica, Arial, sans-serif;
  font-size: 12pt;
}
.container {
	position: absolute;
  top: 0;
  right: 0;
  bottom: 0;
  left: 0;
  background: #aaa;
}
.top {
	background: red;
}
.middle {
  background: yellow;
}
.bottom {
  background: blue;
}
.top, .middle, .bottom {
  position: relative;
  left: 0;
}
.top:hover, .middle:hover, .bottom:hover {
	left: 20px;
}

templates.application.hbs

<div class="container">
  <div class="top">Top</div>
  <div class="middle">Middle</div>
  <div class="bottom">Bottom</div>
</div>

twiddle.json

{
  "version": "0.10.7",
  "EmberENV": {
    "FEATURES": {}
  },
  "options": {
    "use_pods": false,
    "enable-testing": false
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.10.0",
    "ember-data": "2.10.0",
    "ember-template-compiler": "2.10.0",
    "ember-testing": "2.10.0"
  },
  "addons": {}
}