1button {
2  height: 4em;
3  width: 15em;
4  border: none;
5  border-radius: 40px;
6  background-color: #fff;
7}
8
9button span {
10  z-index: 1;
11  display: inline-block;
12  background-color: black;
13  height: 3em;
14  width: 11.5em;
15  border-radius: 25px;
16  color: #fff;
17  line-height: 55px;
18  font-size: 18px;
19  letter-spacing: 3px;
20  transition: all 0.5s;
21}
22
23button .container {
24  z-index: -1;
25  width: 0;
26  position: relative;
27  display: flex;
28  justify-content: center;
29  transform: translateY(-50px);
30  transition: all 0.4s;
31}
32
33button .container svg {
34  padding: 0 10px;
35}
36
37button:hover span {
38  width: 0;
39}
40
41button:hover .container {
42  z-index: 2;
43  width: 100%;
44}