.u-section-1 .u-image-1 {
  min-height: 2130px;
  min-width: 700px; /* falls gewünscht */
  background-image: url("images/Sportangebot.PNG");
  background-position: center center;
  background-repeat: no-repeat;
  background-size: contain; /* ? wichtig */
}

@media (max-width: 1199px) {
  .u-section-1 .u-image-1 {
    min-height: 458px;
  }
}