1.btn {
2  position: relative;
3  padding: 10px 50px;
4  font-size: 20px;
5  border: 1px solid #002B5B;
6  text-transform: uppercase;
7  cursor: pointer;
8  border-radius: 15px;
9  transition: all 0.5s;
10  z-index: 1;
11}
12
13.btn:hover {
14  transform: scale(1.1);
15  color: #fff;
16  transition: all 0.5s;
17}
18
19.btn::after {
20  position: absolute;
21  content: "";
22  top: 50%;
23  left: 50%;
24  width: 0%;
25  height: 100%;
26  border-radius: 15px;
27  background: linear-gradient(#002B5b,#EA5455);
28  transition: all 0.5s;
29  z-index: -1;
30}
31
32.btn:hover::after {
33  top: 0%;
34  left: 0%;
35  width: 100%;
36  transition: all 0.5s;
37}