verflow-x: hidden;

  --main-width: 50rem;
  --nav-width: 20rem;
}

@media (max-width: 70rem) {
    /*For narrow screens hide nav and enable horizontal scrolling */
    nav {display: none;}
    body {overflow-x: auto;}
}

nav {/* this actually just holds space for #navbar, which is fixed */
  min-width: var(--nav-width);
  max-width: var(--nav-width);
}
#navbar {
  position: fixed;
  height: 100vh;
  width: var(--nav-width);
  overflow-y: scroll;
  border-right: 1px solid firebrick;
}
#navbar:before {
  con