#content {
position:relative; 
background-color:transparent;
z-index:100;
}

#content a img {
border:0;
}

#content a.tumb, #content a.tumb:visited {
display:block;
text-decoration:none;
background-color:#fff;
color:#fff;
}

#content a.tumb:hover, #content a.tumb:active {
text-decoration:none; 
background-color:transparent;
color:#fff;
}

#content a .grande, #content a .grande:visited{
display:block;
position:absolute; 
width:1px; 
height:1px; 
top:-1px;
left:-1px;
color:#fff;
background-color:transparent;
}

#content a.tumb:hover .grande, #content a.tumb:active .grande{
display:block; 
position:absolute; 
width:312px;
height:257px;
top:5px;
left:42px;
}