body, html {
  height: 100%;
}
.bg {
  /* The image used */
  background-image: url("https://mdbootstrap.com/img/Photos/Horizontal/Nature/full page/img(11).jpg");

  /* Half height */
  height: 50%;

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