div.gauche { float: left; }
div.droite { float: right; }
div.centre { margin: auto; }

table.diapo {
  border-style: none;
}
table.diapo td {
  border-color: #c0c0c0;
  border-width: 1px;
  border-style: solid;
  text-align: center;
  vertical-align: middle;
  padding: 2px;
}
table.diapo th {
  background-color: #f0e0d0;
  color: black;
  border-color: #c0c0c0;
  border-width: 1px;
  border-style: solid;
  text-align: center;
  vertical-align: middle;
  font-size: smaller;
  padding: 2px;
}