1/* Hide the default checkbox */
2.container input {
3  position: absolute;
4  opacity: 0;
5  cursor: pointer;
6  height: 0;
7  width: 0;
8}
9
10.container {
11  display: block;
12  position: relative;
13  cursor: pointer;
14  font-size: 20px;
15  user-select: none;
16}
17
18/* Create a custom checkbox */
19.checkmark {
20  position: relative;
21  top: 0;
22  left: 0;
23  height: 1.3em;
24  width: 1.3em;
25  background-color: #e5e5e5;
26  border-radius: 50%;
27}
28
29/* When the checkbox is checked, add a blue background */
30.container input:checked ~ .checkmark {
31  background-color: seagreen;
32}
33
34/* Create the checkmark/indicator (hidden when not checked) */
35.checkmark:after {
36  content: "";
37  position: absolute;
38  display: none;
39}
40
41/* Show the checkmark when checked */
42.container input:checked ~ .checkmark:after {
43  display: block;
44}
45
46/* Style the checkmark/indicator */
47.container .checkmark:after {
48  left: 0.45em;
49  top: 0.25em;
50  width: 0.25em;
51  height: 0.5em;
52  border: solid white;
53  border-width: 0 0.15em 0.15em 0;
54  transform: rotate(45deg);
55}