.reference {

     display:flex;

     flex-direction: row;

     flex-wrap: wrap;

}



.se-reference {

     width: 18%;

     position: relative;

     height:20vh;

     margin:1%;

     background-color:white;

}



.se-reference img {

     position: absolute;

     top:0; right:0; bottom:0; left:0;

     margin:auto !important;

     max-width:80%;

     max-height: 80%;

}