div {
  font-family: sans-serif;
  font-size: 16px;
  color: white;
  letter-spacing: -1px;
  width: 100px;
  height: 40px;
  margin-right: 10px;
  border: 1px solid #aaa;
  float: left;
  line-height: 40px;
  text-align: center;
  border-radius: 10px;
  text-transform: uppercase;
  text-shadow: 1px 1px 1px black;
  box-shadow: 2px 2px 5px #ccc;
  padding-top: 2px;
}

.one {
  background-image: url(images/icon.png);
}

.two {
  background-image: -webkit-linear-gradient(top,#aaa,#eee);
  background-image: -moz-linear-gradient(top,#aaa,#eee);
  background-image: -ms-linear-gradient(top,#aaa,#eee);
  background-image: -o-linear-gradient(top,#aaa,#eee);
  background-image: linear-gradient(to bottom,#aaa,#eee);
}

.three {
  background-image: url(images/icon.png), -webkit-linear-gradient(top,#aaa,#eee);
  background-image: url(images/icon.png), -moz-linear-gradient(top,#aaa,#eee);
  background-image: url(images/icon.png), -ms-linear-gradient(top,#aaa,#eee);
  background-image: url(images/icon.png), -o-linear-gradient(top,#aaa,#eee);
  background-image: url(images/icon.png), linear-gradient(to bottom,#aaa,#eee);
}