div.main {
  margin-top: 130px;
  text-align: center;
  font-family: monospace;
  color: #000;
}

span {
  color: #444;
  -webkit-transition:color 2.5s;
  -ms-transition:color 2.5s;
  -o-transition:color 2.5s;
  transition:color 2.5s;
}

span:hover {
  color: #FF0;
  -webkit-transition:color .0s;
  -ms-transition:color .0s;
  -o-transition:color .0s;
  transition:color .0s;
}

span.d {
  color: #FF0;
  -webkit-transition:color .0s;
  -ms-transition:color .0s;
  -o-transition:color .0s;
  transition:color .0s;
}