1.loader {
2  display: block;
3  --height-of-loader: 4px;
4  --loader-color: #0071e2;
5  width: 130px;
6  height: var(--height-of-loader);
7  border-radius: 30px;
8  background-color: rgba(0,0,0,0.2);
9  position: relative;
10}
11
12.loader::before {
13  content: "";
14  position: absolute;
15  background: var(--loader-color);
16  top: 0;
17  left: 0;
18  width: 0%;
19  height: 100%;
20  border-radius: 30px;
21  animation: moving 1s ease-in-out infinite;
22  ;
23}
24
25@keyframes moving {
26  50% {
27    width: 100%;
28  }
29
30  100% {
31    width: 0;
32    right: 0;
33    left: unset;
34  }
35}