spinner css pure

1@keyframes spinner {
2  to {transform: rotate(360deg);}
3}
4 
5.spinner:before {
6  content: '';
7  box-sizing: border-box;
8  position: absolute;
9  top: 50%;
10  left: 50%;
11  width: 20px;
12  height: 20px;
13  margin-top: -10px;
14  margin-left: -10px;
15  border-radius: 50%;
16  border: 2px solid transparent;
17  border-top-color: #07d;
18  border-bottom-color: #07d;
19  animation: spinner .8s ease infinite;
20}

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