1.input {
2  -webkit-appearance: none;
3 /* remove default */
4  display: block;
5  margin: 10px;
6  width: 24px;
7  height: 24px;
8  border-radius: 12px;
9  cursor: pointer;
10  vertical-align: middle;
11  box-shadow: hsla(0,0%,100%,.15) 0 1px 1px, inset hsla(0,0%,0%,.5) 0 0 0 1px;
12  background-color: hsla(0,0%,0%,.2);
13  background-image: -webkit-radial-gradient( hsla(200,100%,90%,1) 0%, hsla(200,100%,70%,1) 15%, hsla(200,100%,60%,.3) 28%, hsla(200,100%,30%,0) 70% );
14  background-repeat: no-repeat;
15  -webkit-transition: background-position .15s cubic-bezier(.8, 0, 1, 1),
16    -webkit-transform .25s cubic-bezier(.8, 0, 1, 1);
17  outline: none;
18}
19
20.input:checked {
21  -webkit-transition: background-position .2s .15s cubic-bezier(0, 0, .2, 1),
22    -webkit-transform .25s cubic-bezier(0, 0, .2, 1);
23}
24
25.input:active {
26  -webkit-transform: scale(1.5);
27  -webkit-transition: -webkit-transform .1s cubic-bezier(0, 0, .2, 1);
28}
29
30
31
32/* The up/down direction logic */
33
34.input,
35.input:active {
36  background-position: 0 24px;
37}
38
39.input:checked {
40  background-position: 0 0;
41}
42
43.input:checked ~ .input,
44.input:checked ~ .input:active {
45  background-position: 0 -24px;
46}