body {
  text-align: center;
  font-family: Arial, Helvetica, sans-serif;
}

@media (prefers-color-scheme: dark) {
  body {
    color: white;
    background: black;
  }
}

h1 {
  letter-spacing: 0.11em;
}

a:link, a:visited {
  background-color: #3399ff;
  color: white;
  padding: 14px 25px;
  width: 200px;
  text-align: center;
  text-decoration: none;
  display: inline-block;
}

a:hover, a:active {
  background-color: #66b3ff;
}