body {
  margin: auto;
}

body a {
  text-decoration: none;
}

nav {
  background: dimgray;
  width: 100%;
}

nav a {
  color: white;
}

nav ul {
  display: flex;
  font-size: x-large;
  justify-content: space-around;
  list-style-type: none;
  margin: auto;
  padding: 10px 0 10px 0;
}

article {
  font-size: large;
  margin: auto;
}

article button {
  font-size: large;
  position: fixed;
}

article button a {
  color: black;
}

article h1 {
  font-size: x-large;
  text-align: center;
}

article h2 {
  font-size: large;
  text-align: center;
}

article img {
  float: right;
}

article pre code {
  background: whitesmoke;
  display: block;
}

@media only screen and (max-width: 959px) {
  nav ul {
    width: 94%;
  }

  article {
    width: 94%;
  }

  article button {
    bottom: 20px;
    right: 20px;
  }

  article img {
    margin-left: 1%;
    width: 40%;
  }

  article pre code {
    font-size: small;
  }
}

@media only screen and (min-width: 960px) {
  nav ul {
    width: 960px;
  }

  article {
    width: 960px;
  }

  article button {
    bottom: 30px;
    right: 40px;
  }

  article img {
    margin-left: 20px;
    width: 240px;
  }

  article ol {
    margin-left: 240px;
  }
}