Thêm hiệu ứng border 4 góc cho ảnh

.image-class:before, .image-class:after {
    bottom: 10px;
    content: "";
    left: 10px;
    opacity: 0;
    position: absolute;
    right: 10px;
    top: 10px;
    -webkit-transition: opacity .35s ease 0s,transform .35s ease 0s;
    -o-transition: opacity .35s ease 0s,transform .35s ease 0s;
    transition: opacity .35s ease 0s,transform .35s ease 0s;
    z-index: 1;
}
.image-class:before {
    border-bottom: 1px solid #fff;
    border-top: 1px solid #fff;
    -webkit-transform: scale(0,1);
    -ms-transform: scale(0,1);
    -o-transform: scale(0,1);
    transform: scale(0,1);
}
.image-class:hover:before, .image-class:hover:after {
    opacity: 1;
    filter: alpha(opacity=100);
    /* -webkit-transform: scale(1); */
    -ms-transform: scale(1);
    -o-transform: scale(1);
    transform: scale(1);
}