.aiot-welcome {
  height: 700px;
  color: #fff;
  background: url('/resource/images/welcome-aiot-bg.jpg') center center no-repeat;
  background-size: auto 100%;
}
.aiot-invitation {
  height: 400px;
  background: url('/resource/images/aiot-invitation-bg.png') center center no-repeat;
  background-size: 100% 100%;
}