Style CHARKMARK CSS

label input {
  visibility: hidden;/* <-- Hide the default checkbox. The rest is to hide and allow tabbing, which display:none prevents */
  display: block;
  height: 0;
  width: 0;
  position: absolute;
  overflow: hidden;
}
label span {/* <-- Style the artificial checkbox */
  height: 10px;
  width: 10px;
  border: 1px solid grey;
  display: inline-block;
}
[type=checkbox]:checked + span {/* <-- Style its checked state */
  background: black;
}
Karol Sobkowicz