.page-inner {
  max-width: 1000px !important;
}

.book.font-size-0 .book-body .page-inner section {
  font-size: 1em !important;
}
.book.font-size-1 .book-body .page-inner section {
  font-size: 1.5em !important;
}
.book.font-size-2 .book-body .page-inner section {
  font-size: 2em !important;
}
.book.font-size-3 .book-body .page-inner section {
  font-size: 2.5em !important;
}
.book.font-size-4 .book-body .page-inner section {
  font-size: 3em !important;
}