how to use pseudo class css in button code example

Example: add pseudo buttons

.checkbox-wrapper label::before, .radio-wrapper label::before {
  content: "";
  height: 20px;
  width: 20px;
  background: rgba(255, 255, 255, 0.75);  
  border: 1px solid #024e76;  
  position: absolute;
  top: -4px;
  left: -30px;
}