body{
color: white;
background-color: black;
text-align: center;
}

body *{
margin-left:auto;
margin-right:auto;
}

.warning, .exit{
color: red;
font-weight: bold;
}

.exit{
  margin-left: 5em;
}

.enter{
color: green;
font-weight: bold;
font-size: 2em;
}