.zentriert {
     position: absolute;
     top: 50%;
     left: 50%;
     width: 250px;
     height: 150px;
     padding: 20px;
     margin-left: -100px;
     margin-top: -100px;
     background: #fff;
     box-sizing: border-box;
}
.zentr {
     position: relative;
     top: 15%;
     left: 0%;
     width: 60%;
     height: 60%;
     /*padding: 20px;*/
     margin-left: 0px;
     margin-top: 0px;
     /*background: #fff;*/
     box-sizing: border-box;
}