.loading #app {
  position: absolute;
  left: 0;
  right: 0;
  top: 0;
  bottom: 0;
  background: url(./loader.jpg) no-repeat left top;
  background-size: cover;
}
.loading .loader {
  position: absolute;
  left: 50%;
  top: 50%;
  transform: translate(-50%, -50%);
  text-align: center;
  font-size: 16px;
  color: #fff;
  text-shadow: 1px 1px 0px #000;
}