div.mostrador{
    position: relative;
    margin: auto;
    width: 900px;
    height: 600px;
    top: 100px;
}

div.gallery {
    margin: 10px;
    border: 10px;
    float: left;
    width: 185px;
}


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

div.desc {
    padding: 15px;
    text-align: center;
}

div.gallery:hover {
    border: 10px;
}