button {
  align-items: center;
  background-color: transparent;
  color: #fff;
  cursor: pointer;
  display: flex;
  font-family: ui-sans-serif,system-ui,-apple-system,system-ui,"Segoe UI",Roboto,"Helvetica Neue",Arial,"Noto Sans",sans-serif,"Apple Color Emoji","Segoe UI Emoji","Segoe UI Symbol","Noto Color Emoji";
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.5;
  text-decoration: none;
  text-transform: uppercase;
  outline: 0;
  border: 0;
  padding: 1rem;
}

button:before {
  background-color: #fff;
  content: "";
  display: inline-block;
  height: 1px;
  margin-right: 10px;
  transition: all .42s cubic-bezier(.25,.8,.25,1);
  width: 0;
}

button:hover:before {
  background-color: #fff;
  width: 3rem;
}