body {
  margin: 0;
  padding: 0;
  background: #c0c0c0;
}

main {
  width: 65rem;
  margin-left: 240px;
  margin-bottom: 60px;
}

aside {
  width: 200px;
  position: fixed;
  top: 0;
  bottom: 0;
  padding: 8px;
  display: flex;
  align-items: stretch;
}

aside .tree-view {
  width: 100%;
  /* TODO: Move scrollbar into the recessed region? */
  overflow-y: scroll;
}

h1 {
  margin: 12px 0;
}

hr {
  margin: 0;
  border: none;
  width: 400px;
  height: 1px;
  opacity: 0.5;
  background: linear-gradient(
    to right,
    red 20%,
    yellow 20%,
    yellow 36%,
    green 36%,
    green 60%,
    blue 60%,
    blue 100%
  );
}

h2 {
  margin-bottom: 12px;
}

h3 {
  font-size: 1.6rem;
}

h3,
h4 {
  /* Swap the margin for a top-padding so linking to this section
     results in a better scroll position */
  padding-top: 20px;
  margin-top: 0;
  display: block;
  flex: 0 0 180px;
}

p {
  max-width: 50rem;
  line-height: 1.5;
}

.component {
  display: flex;
  margin-top: 24px;
}

blockquote {
  margin: 0 0 20px;
  padding: 20px;
  background: #dfdfdf;
}

blockquote footer {
  margin: 12px 0 0 12px;
}

.example {
  margin: 16px 0;
  padding: 12px 24px;
  border-left: 1px solid #808080;
}

details {
  margin-top: 12px;
}

summary {
  user-select: none;
  cursor: pointer;
  display: inline;
}

details[open] summary {
  margin-bottom: 8px;
}

button.focused {
  outline: 1px dotted #000000;
  outline-offset: -4px;
}

button.active {
  border-image: url("data:image/svg+xml;charset=utf-8,%3Csvg width='5' height='5' xmlns='http://www.w3.org/2000/svg'%3E%3Cpath fill='%230a0a0a' d='M0 0h4v1H0z'/%3E%3Cpath fill='%230a0a0a' d='M0 0h1v4H0z'/%3E%3Cpath fill='gray' d='M1 1h2v1H1z'/%3E%3Cpath fill='gray' d='M1 1h1v2H1z'/%3E%3Cpath fill='%23fff' d='M0 4h5v1H0z'/%3E%3Cpath fill='%23fff' d='M4 0h1v5H4z'/%3E%3Cpath fill='%23dfdfdf' d='M3 1h1v3H3z'/%3E%3Cpath fill='%23dfdfdf' d='M1 3h3v1H1z'/%3E%3C/svg%3E") 2;
  text-shadow: 1px 1px #222;
}

@media (max-width: 480px) {
  aside {
    display: none;
  }

  main {
    box-sizing: border-box;
    width: 100%;
    margin: 0;
    padding: 16px;
  }

  hr {
    width: 100%;
  }

  p {
    width: 100%;
  }

  h3,
  h4 {
    flex: 0;
  }

  .component {
    display: block;
    margin-top: 24px;
  }

  pre {
    overflow-x: scroll;
  }
}