body {
  background-color: #333;
  font-family: "Segoe UI", "Arial";
  font-variant: small-caps;
  color: lightgrey;
  display: flex;
  flex-direction: column;
  align-items: center;
}

a {
  color: violet;
}

a:hover {
  color: magenta;
}

.flex {
  display: flex;
}

.mainbox {
  background-image: linear-gradient(#555, #222);
  border: 1px solid black;
  padding: 10px;
  max-width: 400px;
  margin-top: 10px;
}