1.loader {
2  width: 150px;
3  height: 150px;
4  border-radius: 50%;
5  position: relative;
6  box-shadow: 0 0 30px 4px rgba(0, 0, 0, 0.5) inset,
7      0 5px 12px rgba(0, 0, 0, 0.15);
8  overflow: hidden;
9}
10
11.loader:before,
12  .loader:after {
13  content: "";
14  position: absolute;
15  width: 100%;
16  height: 100%;
17  border-radius: 45%;
18  top: -40%;
19  background-color: #2e2e2e;
20  animation: wave 5s linear infinite;
21}
22
23.loader:before {
24  border-radius: 30%;
25  background: rgba(122, 122, 122, 0.4);
26  animation: wave 5s linear infinite;
27}
28
29@keyframes wave {
30  0% {
31    transform: rotate(0);
32  }
33
34  100% {
35    transform: rotate(360deg);
36  }
37}