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: 2.3em;
24  width: 2.3em;
25  background-color: #ccc;
26  border-radius: 50%;
27  transition: .4s;
28}
29
30.checkmark:hover {
31  box-shadow: inset 17px 17px 16px #b3b3b3,
32            inset -17px -17px 16px #ffffff;
33}
34
35/* When the checkbox is checked, add a blue background */
36.container input:checked ~ .checkmark {
37  box-shadow: none;
38  background-color: limegreen;
39  transform: rotateX(360deg);
40}
41
42.container input:checked ~ .checkmark:hover {
43  box-shadow: 3px 3px 3px rgba(0,0,0,0.2);
44}
45
46/* Create the checkmark/indicator (hidden when not checked) */
47.checkmark:after {
48  content: "";
49  position: absolute;
50  display: none;
51}
52
53/* Show the checkmark when checked */
54.container input:checked ~ .checkmark:after {
55  display: block;
56}
57
58/* Style the checkmark/indicator */
59.container .checkmark:after {
60  left: 0.96em;
61  top: 0.7em;
62  width: 0.25em;
63  height: 0.5em;
64  border: solid white;
65  border-width: 0 0.15em 0.15em 0;
66  box-shadow: 0.1em 0.1em 0em 0 rgba(0,0,0,0.3);
67  transform: rotate(45deg);
68}