.book .book-body .page-wrapper .page-inner {
  max-width: 900px;
}

blockquote {
  border-left: 4px solid #777;
  padding-left: 1em;
  color: #444;
}

.note {
  background: #f7f7f7;
  border-left: 4px solid #999;
  padding: 1em;
  margin: 1em 0;
}