One day you'll find yourself spending several weeks making a "PWA book framework". When you do this, keep in mind that text is small and the network is slow, so

One day you'll find yourself spending several weeks making a "PWA book framework". When you do this, keep in mind that text is small and the network is slow, so store the whole book on one webpage and do pagination by switching which parts are visible. This way, the PWA book will be much more responsive and it will also work offline.