@media (min-width: 64em) {
  header img {
    width: 140px;
  }

  header h1 {
    font-size: 50px;
  }

  header h2 {
    font-size: 28px;
  }

  main {
    max-width: 64em;
    margin: auto;
  }

  footer {
    max-width: 66em;
    margin: auto;
  }

  nav button {
    display: none;
  }

  nav ul,
  nav ul.hidden {
    display: flex;
    border-top: none;
  }

  nav ul li {
    flex: 1 1 100%;
  }

  nav ul li a {
    font-size: 18px;
    padding: 1em;
  }

  nav ul li.current a {
    box-shadow: 0 2px 0 hsl(40, 80%, 30%);
  }

  nav ul li:hover a {
    box-shadow: 0 4px hsl(40, 80%, 30%);
  }
}