body {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  font-family: sans-serif;
}

.btn {
  padding: 20px 40px;
  text-transform: uppercase;
  border: 2px solid #e91e63;
  color: #e91e63;
  text-decoration: none;
  border-radius: 25px;
  position: relative;
  overflow: hidden;
  transition: color 0.5s ease;
}

.btn::before {
  content: '';
  width: 100%;
  height: 100%;
  background-color: #e91e63;
  position: absolute;
  top: 0;
  left: 0;
  transform: translateX(-100%);
  transition: transform 0.5s ease;
  z-index: -1;
}

.btn:hover {
  color: white;
}
.btn:hover::before {
  transform: translateX(0);
}