css circle checkbox

1.checkbox-round {
2    width: 1.3em;
3    height: 1.3em;
4    background-color: white;
5    border-radius: 50%;
6    vertical-align: middle;
7    border: 1px solid #ddd;
8    -webkit-appearance: none;
9    outline: none;
10    cursor: pointer;
11}
12
13.checkbox-round:checked {
14    background-color: gray;
15}