<div class="container">
    <div class="iframe-container">
        <iframe title="Sketchfab Viewer" src="" id="api-frame"></iframe>
     </div>
     <div class="controls" id="controls">
       <pre id="Info"></pre>
     </div>
</div>

html, body {
    padding: 0;
    margin: 0;
    width: 100vw;
    height: 100vh;

    -webkit-font-smoothing: antialiased;
    -moz-font-smoothing: grayscale;
    font-family: Open Sans, sans-serif;
}

* {
    box-sizing: border-box;
}

.container {
    display: flex;
    flex-direction: column;
    height: 100%;
}

.iframe-container {
    position: relative;
    width: 100%;
    flex: 1;
    display: flex;
}

.iframe-container > iframe {
    border: 0;
    width: 100%;
    flex: 1;
}

.controls {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    flex-shrink: 0;
    height: 80px;
    padding: 15px 0 0 15px;
    background-color: #000000;
    border-top: 1px solid #e7e7e7;
    overflow: scroll;
}

.controls > * {
    margin-right: 15px;
    margin-bottom: 15px;
}

button {
    display: inline-flex;
    justify-content: center;
    align-items: center;
    position: relative;
    border: 2px solid transparent;
    border-radius: 4px;
    padding: 0 13px;
    font-family: "Open Sans", sans-serif;
    font-weight: 600;
    text-align: center;
    text-shadow: none;
    text-transform: uppercase;
    line-height: 1.2;
    cursor: pointer;
    outline: none;
    transition: background .2s;
    color: white;
    background-color: #1caad9;
    height: 25px;
    font-size: 12px;
}

button.disabled {
    cursor: default;
    pointer-events: none;
    color: #ccc;
    background-color: #e7e7e7;
    transition: background-color .25s ease;
}

.description {
    box-sizing: border-box;
    position: absolute;
    padding: 30px;
    top: 30px;
    right: 30px;
    width: 240px;
    background: rgba(0, 0, 0, 0.6);
    color: #ffffff;
    border-radius: 3px;
    z-index: 2;

    opacity: 0;
    pointer-events: none;
}

.description.--active {
    opacity: 1;
    pointer-events: all;
}

.description iframe,
.description img {
    max-width: 100%;
    height: auto;
}

// Sketchfab Viewer API: Start/Stop the viewer
var version = '1.10.3';
var uid = '154d1a04fbb7482186d19ebd8c984361';
var iframe = document.getElementById('api-frame');
var client = new window.Sketchfab(version, iframe);

var error = function error() {
  console.error('Sketchfab API error');
};

var success = function success(api) {
  api.addEventListener('viewerstart', function () {
    console.log('viewerstart');
  });
  api.addEventListener('viewerstop', function () {
    console.log('viewerstop');
  });
  api.start(function () {
    document.getElementById('start').addEventListener('click', function () {
      api.start();
    });
    document.getElementById('stop').addEventListener('click', function () {
      api.stop();
    });

    api.addEventListener('viewerready', function () {
      console.log('viewerReady');
    });
  });
};

client.init(uid, {
  success: success,
  error: error,
  autostart: 1,
  preload: 1
}); //////////////////////////////////
// GUI Code
//////////////////////////////////

function initGui() {
  var controls = document.getElementById('controls');
  var buttonsText = '';
  buttonsText += '<button id="start">Start</button>';
  buttonsText += '<button id="stop">Stop</button>';
  controls.innerHTML = buttonsText;
}

initGui();