div.img {
    margin: 5px;
    border: .4em solid silver;
    float:left;
    width:45%;
}	

div.img:hover {
    border: .4em double black;
}

div.img img {
    width: 100%;
    height: auto;
}

div.desc {
    padding: 1em;
    text-align: center;
}