@media only screen and (min-width: 768px) {
  header h1 {
    font-size: 2.85rem;
  }
  header h2 {
    font-size: 1.5rem;
  }
  header img {
    height: 70px;
  }

  .medium-6 {
    width: 50%;
  }

  .medium-5 {
    width: 20%;
  }
  nav button {
    display: none;
  }
  nav ul {
    display: block;
  }
  nav li {
    width: 10%;
    float: left;
  }
} /* end of media query */