1/* Customize the label (the container) */
2.container {
3 display: block;
4 position: relative;
5 cursor: pointer;
6 font-size: 22px;
7 user-select: none;
8}
9
10/* Hide the browser's default checkbox */
11.container input {
12  position: absolute;
13  opacity: 0;
14  cursor: pointer;
15  height: 0;
16  width: 0;
17}
18
19/* Create a custom checkbox */
20.checkmark {
21  position: absolute;
22  top: -12px;
23  left: -12px;
24  height: 25px;
25  width: 25px;
26  background-color: #ccc;
27  border: solid gray 1px;
28  border-radius: 4px;
29}
30
31/* When the checkbox is checked, add a blue background */
32.container input:checked ~ .checkmark {
33  background-color: #666666;
34}
35
36/* Create the checkmark/indicator (hidden when not checked) */
37.checkmark:after {
38  content: "";
39  position: absolute;
40  display: none;
41}
42
43/* Show the checkmark when checked */
44.container input:checked ~ .checkmark:after {
45  display: block;
46}
47
48/* Style the checkmark/indicator */
49.container .checkmark:after {
50  left: 0.4rem;
51  top: 0.2rem;
52  width: 6px;
53  height: 10px;
54  border: solid white;
55  border-width: 0 3px 3px 0;
56  transform: rotate(45deg);
57}