.content-block {
  background-color: black;
  background-size: cover;
  background-position: center center;
  background-repeat: no-repeat;
    background-image: url(https://vinterstigen.se/css/bkg4.jpg);
    width: 100%;
    height: 100%;
}

html,body {
    height:100%;
    overflow-y: hidden;
    overflow-x: hidden;
}