body {
    background-image: url("/schule/login/karte-min.jpg");
    background-size:     cover;
    background-repeat:   no-repeat;
}
body::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background-color: rgba(255, 255, 255, 0.75); /* Passe die Farbe und die Transparenz an */
  z-index: -9999;
  height: 150%;
}