[type="checkbox"] + label {
  position: absolute;
}
[type="checkbox"] {
  position: relative;
  left: 15px;
  top: -4px;
  z-index: 0;
  -webkit-appearance: none;
}
[type="checkbox"] + label::before {
  width: 22px;
  height: 18px;
  background-image: url("/sammlung/bilder/icon/cbunchecked.php");
  display: block;
  content: "";
  float: left;
  margin-right: 5px;
  z-index: 5;
  position: relative;
}
[type="checkbox"]:checked+label::before {
  background-image: url("/sammlung/bilder/icon/cbchecked.php");
}