input[type=checkbox] {
  position: absolute;
  clip: rect(0, 0, 0, 0);
}
label {
  cursor: pointer;
}
label:after {
  content: ' ';
  display: inline-block;
  width: 17px;
  height: 17px;
  background: url('/images/checkbox-2.png');
  position: relative;
  top: 3px;
  margin-left: 15px;
}

input[type=checkbox]:checked + label:after {
background-position: 0 -17px;
}
label:hover:after {
background-position: 0 -34px;
}
input[type=checkbox]:checked + label:hover:after {
background-position: 0 -51px;
}