.header {
    font-size: xx-large;
    color:navy;
    text-align: center;
    font-family: Arial;
}
body {
    background-color: rgb(183, 185, 185);     
    height: 604px;
    width: 868px;
    background-position: center; 
    background-repeat: repeat; 
  }
  button {
      background-color: lightgrey;
      color: navy;
      font-size: 20px;
      margin: 5px;
  }