/* boutton ouvrir pop up */

#bu-bu
{
  float: left;
  width:200px;
  max-width: 300px;
  margin-top: 12px;
  border: 2px solid #f7f7f7;
  background-color: #383838;
  padding: 10px;
  cursor: pointer;
  color: #f7f7f7;
  font-family: tahoma;
  text-transform: uppercase;
  font-size: 18px;
  letter-spacing: 3px;
   -webkit-transition: 0.5s;
  -moz-transition: 0.5s;
  -ms-transition: 0.5s;
  -o-transition: 0.5s;
  transition: 0.5s;
}

#bu-bu:hover
{
  background-color: #292929;
  color: #fff;
}