[role='checkbox'] {
   margin: 0;
   padding: 0.25em;
   padding-left: 0.5em;
   border: 2px transparent solid;
   width: 12em;
}

[role='checkbox'][aria-checked='false']:before{
   content: url('../images/checkbox-unchecked.png');
   position: relative;
   top: 2px;
   left: -0.25em;
}

[role='checkbox'][aria-checked='true']:before{
   content: url('../images/checkbox-checked.png');
   position: relative;
   top: 2px;
   left: -0.25em;
}

[role='checkbox']:hover {
   background-color: #DDDDDD;
}

[role='checkbox'].focus {
   border-color: black;
   background-color: #EEEEEE;
}