.themen-header .image-header { background-image: url('/fileadmin/user_upload/Themen/quamath/quamath-hauptbanner-hq.jpg'); }

@media only screen and (max-width: 1024px) {.themen-header .image-header { background-image: url('/fileadmin/user_upload/Themen/quamath/quamath-hauptbanner-small.jpg'); }}