style.css

body {
  background: -webkit-linear-gradient(top left, #50a3a2 0%, #53e3a6 100%);
}

button {
  appearance: none;
  outline: 0;
  background-color: white;
  border: 0;
  padding: 10px 15px;
  color: #53e3a6;
  border-radius: 3px;
  width: 250px;
  cursor: pointer;
  font-size: 18px;
  transition-duration: 0.25s;
}
button:hover {
  background-color: rgb(245, 247, 249);
}