.container-header {
    background-image: linear-gradient(to left top, #4128FF, #4128FF); /* change color */
}
.container-top-a {
 background-color: #CCCCCC;
}
header.site-header {
    padding-top: 0.5rem !important;   /* vorher oft 2rem oder mehr */
    padding-bottom: 0.5rem !important;
}