body, html {
  min-height: 100%;
}
.bg {
  /* The image used */
  background-image: url("http://app-25190b53-be22-4ea0-97e8-96c8e4f49797.cleverapps.io/img/accueil-page-connexion.jpg");

  /* Full height */
  /*height: 100%;*/

  /* Center and scale the image nicely */
  background-position: center;
  background-repeat: no-repeat;
  background-size: cover;
}