CSS transition example

gistfile1.css

/* -- boxel --------------------------- */

.boxel {
  background-color: #eee;
  border-radius: 4px;
  padding: 10px 0;
  color: #666;
  text-align: center;
  -webkit-transition: background-color 0.25s linear;
  -moz-transition: background-color 0.25s linear;
  transition: background-color 0.25s linear;
}

.boxel-darkgrey {
  background-color: #ccc;
}

.boxel:hover {
  background-color: #ccc;
  -webkit-transition: background-color 0.25s linear;
  -moz-transition: background-color 0.25s linear;
  transition: background-color 0.25s linear;
}