body {
  margin: 0;
}

#navbar {
  position: fixed;
  left: 0;
  top: 0;
  width: auto;
  height: 100vh;
  background: #f4f4f4;
  padding: 1rem;
}

#main-doc {
  margin-left: 350px;
  padding: 1rem;
}
#navbar a {
  display: block;
  color: black;
  text-decoration: none;
  padding: 0.5rem 8px;
  border-top: 1px solid black;
}

#navbar a:last-child {
  border-bottom: 1px solid black;
  padding: 0.5rem;
}

code {
  background-color: #f4f4f4;
}

header {
  font-weight: bold;
  padding: 0.5rem 8px;
}

#headerNav {
  text-align: center;
}

@media (max-width: 621px) {
  #navbar {
    display: none;
  }
  #main-doc {
    margin-left: 0;
  }
}