/* Remove this if you dont want background overlay over the image or adjust per your needs */
body.login_admin:before {
    content: " ";
    background: #ebecf0;
    min-height: 100%;
    min-width: 100%;
    position: absolute;
}
body.login_admin {
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
  background-size: cover;
}