body {
  background-color: grey;
  color: white;
  font-family: Verdana;
}

main {
  width: 500px;
  margin: 5rem auto;
  padding: 2rem;
  outline: 1px dashed yellow;
}

h1, h2, #credits {
 text-align: center; 
}

ul {
  margin: 1rem auto;
}