1.btn {
2  display: inline-block;
3  font-family: sans-serif;
4  font-weight: 600;
5  font-size: 16px;
6  color: #fff;
7  margin: 1rem auto;
8  padding: 0.7rem 2rem;
9  border-radius: 30em;
10  border-style: none;
11  position: relative;
12  z-index: 1;
13  overflow: hidden;
14  text-decoration: none;
15  text-transform: uppercase;
16  letter-spacing: 2px;
17  background-color: transparent;
18  box-shadow: 1px 1px 12px #000000;
19}
20
21.btn::before {
22  content: "";
23  width: 100%;
24  height: 100%;
25  position: absolute;
26  top: 0;
27  left: 0;
28  background-color: #fff;
29  transform: translateX(-101%);
30  transition: all .3s ease;
31  z-index: -1;
32}
33
34.btn:hover {
35  color: #272727;
36  transition: all .3s ease;
37}
38
39.btn:hover::before {
40  transform: translateX(0);
41}