@media only screen and (max-width: 450px) {
  h1 {
    padding: 1rem;
  }

  nav {
    flex-direction: column;
    padding: 1rem;
  }

  nav a {
    display: block;
    padding: 0.5rem;
    font-size: 22px;
  }

  main {
    flex-direction: column;
  }
}