checkbox на псевдоэлементах и юникоде
input[type="checkbox"]{
position: relative;
visibility: hidden;
&:after {
content:'\2610';
position: absolute;
left:0;
top:0;
visibility: visible;
}
&:checked:before{
content:'\2713';
font-size: 1.5em;
position: absolute;
left:0;
top:-.5rem;
visibility: visible;
}
}