html, body, #wrapper {
   height:100%;
   width: 100%;
   margin: 0;
   padding: 0;
   border: 0;
}
#wrapper td {
   vertical-align: middle;
   text-align: center;
}
#wrapper td img {
    max-width: 300px;
}
@media (max-width: 620px) {
    #wrapper td img {
        max-width: 100%;
    }
}