#ember-testing-container {
  position: relative;
  background: white;
  bottom: 0;
  right: 0;
  width: 640px;
  height: 384px;
  overflow: auto;
  z-index: 98;
  border: 1px solid #ccc;
  margin: 0 auto;
  transform: translateZ(0);
}

#ember-testing-container.full-screen {
  width: 100%;
  height: 100%;
  overflow: auto;
  z-index: 98;
  border: none;
}

#ember-testing {
  width: 200%;
  height: 200%;
  transform: scale(0.5);
  transform-origin: top left;
}

.full-screen #ember-testing {
  position: absolute;
  width: 100%;
  height: 100%;
  transform: scale(1);
}

#ember-testing-container {
  position: relative;
  background: white;
  bottom: 0;
  right: 0;
  width: 640px;
  height: 384px;
  overflow: auto;
  z-index: 98;
  border: 1px solid #ccc;
  margin: 0 auto;

  /* Prevent leaking position fixed elements outside the testing container */
  transform: translateZ(0);
}

#ember-testing-container.full-screen {
  width: 100%;
  height: 100%;
  overflow: auto;
  z-index: 98;
  border: none;
}

#ember-testing {
  width: 200%;
  height: 200%;
  transform: scale(0.5);
  transform-origin: top left;
}

.full-screen #ember-testing {
  position: absolute;
  width: 100%;
  height: 100%;
  transform: scale(1);
}

Add code comment explaining why the CSS transform is there
Add code comment explaining why the CSS transform is there
