.pretty-checkbox {
  width: 0;
  height: 0;
  position: absolute;
  top: -1000px;
  left: -1000px;
}

.pretty-checkbox + .pretty-checkbox-mark {
    display: inline-block;
    width: 22px;
    height: 22px;
    border: solid black 2px;
    vertical-align: middle;
    margin-right: 12px;
    cursor: pointer;
}

.pretty-checkbox:checked + .pretty-checkbox-mark {
    border-color: #BDBDBD;
    background-color: green;
}