.couverture_archive {
  border: 2px solid black;
  margin-left: 10px;
  margin-top: 10px;
  float: left;
}

.couverture_archive:hover {
  border: 2px solid #F00;
}


#centre_gauche_archives {
  float: left;
  width: 560px;
  background-color: #535353;
  background-image: url('../img/degrade_gris.jpg');
  background-repeat: repeat-x;
  background-position: bottom left;
  padding-bottom: 100px;
  
}

#centre_droit_archives {
  float: left;
  width: 285px;
  background-color: #D8D8D8;
}