.themen-header .image-header { background-image: url('/fileadmin/user_upload/Themen/KI_02/KI-Headergrafik.jpg'); }

@media only screen and (max-width: 1024px) {.themen-header .image-header { background-image: url('/fileadmin/user_upload/Themen/KI_02/KI-Headergrafik_small.jpg'); }}