.one {
  background: #555;
  background: -moz-linear-gradient(top, #555 0%, #000 100%);
  background: -webkit-gradient(linear, left top, left bottom, color-stop(0%, #555), color-stop(100%, #000));
  background: -webkit-linear-gradient(top, #555 0%, #000 100%);
  background: -o-linear-gradient(top, #555 0%, #000 100%);
  background: -ms-linear-gradient(top, #555 0%, #000 100%);
  background: linear-gradient(top, #555 0%, #000 100%);
  filter: unquite("progid:DXImageTransform.Microsoft.gradient( startColorstr='#555', endColorstr='#000',GradientType=0 )");
}
body {
  width: 100%;
  height: 10%;
}
div {
  background: #555;
}
div:hover {
  background: #000;
}
