style.css

.button a {
  /* text-style */
  font-size: 12px;
  color: #03c;
  text-align: center;
  text-decoration: none;
  line-height: 100%;

  /* block-style */
  display: block;
  width: 70px;
  margin: 0 auto;
  padding: 3px 0;

  /* extends-style */
  border: 1px solid #ccc;
  border-radius: 5px;
  -webkit-border-radius: 5px;
  -moz-border-radius: 5px;
  background: -moz-linear-gradient( top, #fff, #ccc );
  background: -webkit-gradient( linear, center top, center bottom, from(#fff), to(#ccc) );
}
.button a:hover {
  background: -moz-linear-gradient( top, #ccc, #fff );
  background: -webkit-gradient( linear, center top, center bottom, from(#ccc), to(#fff) );
}