#ember-testing-container {
  position: absolute;
  background: white;
  bottom: 0;
  right: 0;
  width: 640px;
  height: 384px;
  overflow: auto;
  z-index: 9999;
  border: 1px solid #ccc;
}
#ember-testing {
  zoom: 50%;
}

#ember-testing-container {
  position: fixed;
  background: white;
  bottom: 0;
  right: 0;
  width: 640px;
  height: 384px;
  overflow: auto;
  z-index: 9999;
  border: 1px solid #ccc;
}
#ember-testing {
  zoom: 50%;
}

Fix position of Ember testing root element.
Fix position of Ember testing root element.

The CSS provided by mocha differs from qunit's so absolute
positioning doesn't work.
