.alt {
  z-index: 1;
  display: block;
  visibility: hidden;
  position: absolute;
  left: 0px;
  top: 0px;
  margin: 0px;
  padding: 0px;
}
.alt img {
  border: 1px solid #000000;
}

.vignette a {
  display: block; 
}
.vignette a:hover {
  border: 0px solid #000000;
}
.vignette a img.zoom {
  height: 0;
  width: 0;
  border: 0px solid #000000;
}
.vignette a:hover img.zoom {
  position: absolute; 
  top: -50px; 
  left: -200px; 
  border: 1px solid #000000;
  height: 300px;
  width: 201px;
}