app-root {
  display: block;
  height: 100%;
}
app-root > div {
  background: rgba(255, 255, 255, 0.9);
  z-index: 2;
  position: absolute;
  top: 50%; left: 50%;
  transform:translate(-50%, -50%);
  text-align: center;
}
app-root > div span {
  display: block;
}