.img1 img {
    width:100%;
}

.img2 img {
    position: relative;
    display: block;
    margin-left: auto;
    margin-right: auto;
    z-index: 1;
    width: 140px;
    height: 140px;
    border-radius: 50%;
    border: 7px solid rgba(255, 255, 255, 0.763);
    margin-top: -70px;
}

.card:hover .img2 img {
   border-color: gray;
   transition: .7s; 
}