body{
  background-color: #00A86B;
  }

button{
  color: purple;
  font-size: 21px;
  display: block;
  margin: auto;
  }

h1{
  text-align: center;
  color: lightgreen;
  background-color: gray;
}

h2 {
  text-align: center;
  color: white;
}

.center {
  display: block;
  margin-left: auto;
  margin-right: auto;
  width: 50%;
}