Positioning check

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;
}

.outer {
  width: 100px;
  height: 100px;
  padding: 10px;
  background-color: hsl(231,50%,50%);
  position: relative;
}

.inner {
  position: relative;
  width: 100px;
  height: 50px;
  background-color: hsl(131,50%,50%);
}

.inner2 {
  
  width: 100px;
  height: 50px;
  background-color: hsl(1,50%,50%);
}

.bottom-float {
  position: absolute;
 	bottom: 0px; 
}

templates.application.hbs

<br>
<div class="outer">
  <div class="inner">
  	<div class="bottom-float">
    	Hello world
    </div>
  </div>
  <div class="inner2">
  
  </div>
</div>
<br>
<br>

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"
  }
}