.referans {
    -webkit-transition: all 1s ease;
    -moz-transition: all 1s ease;
    -o-transition: all 1s ease;
    -ms-transition: all 1s ease;
    transition: all 1s ease;
}

.referans:hover {
    -webkit-filter: grayscale(100%);
    box-shadow: 0px 0px 6px #fece00;
    border-radius: 3px;
}