New Twiddle

components.input-range.js

import Ember from 'ember';

export default Ember.Component.extend({
  applyBackground() {
    let el = this.$('input'),
        val = parseInt(el.val()),
        min = parseInt(el.attr('min')),
        max = parseInt(el.attr('max'));
      let valPercent = (val - min) / 
                      (max - min);
    let style = `background-image: -webkit-gradient(linear, 0% 0%, 100% 0%, color-stop(${valPercent}, #3498db), color-stop(${valPercent}, #f5f6f8));`;
    el[0].style = style;
  },
  didInsertElement: function() {
    this.applyBackground();
    let self = this;
    this.$('input').on('input', function(e) {
      self.applyBackground();
    });
  }
});

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;
}

.__range {
  -webkit-appearance: none;
  width: 100%;
  margin: 5.8px 0;
  background-color: #049ee0;
}
.__range:focus{
  outline:none;
}

.__range::-webkit-slider-runnable-track {
  width: 100%;
  height: 8.4px;
  cursor: pointer;
  box-shadow: 1.5px 1.5px 3.5px #000000, 0px 0px 1.5px #0d0d0d;
/*   background: #3498db; */
  border-radius: 1.3px;
  border: 0.2px solid #010101;
}

.__range::-webkit-slider-thumb {
  box-shadow: 2.7px 2.7px 8px #000000, 0px 0px 2.7px #0d0d0d;
  border: 3.6px solid #ffffff;
  height: 20px;
  width: 20px;
  border-radius: 20px;
  background: #3498db;
  cursor: pointer;
  -webkit-appearance: none;
  margin-top: -6px;
}
}

templates.application.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{input-range}}
<br>
<br>

templates.components.input-range.hbs

<input class='__range' type='range' min=1 max=10 />

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"
  }
}