.partenaires{
    clear: both;
    margin-bottom: 20px;
}
.partenaires img{    border: 2px solid #e1e1e1;margin-bottom:5vh;width:100%;}

@media only screen and (max-width: 768px){

.partenaires img {width: 100%;max-width: 250px;margin: 0 auto 5vh;display:block;}

}