Interactive Offline EPUB Builder

I’m putting together an EPUB 3 book for distribution on BookFusion and need a developer who can make the whole experience completely self-contained. All JavaScript, CSS, fonts, and images have to live inside the package—no external CDN calls, no server-side components. Once the reader downloads the file, everything must work offline.

The manuscript itself is already drafted in plain XHTML with images, but I want to enrich it with multiple-choice quizzes sprinkled throughout the chapters. Each question should display immediate on-page feedback: the moment a reader selects an answer they see whether it’s correct or not, followed by a concise explanation of why. No “Submit” button, no page reloads—just smooth, in-context interaction.

Key points the finished EPUB must satisfy:
• EPUB-3 compliant and passes epubcheck
• Works flawlessly on BookFusion’s reader (desktop, mobile, and web)
• Multiple-choice widgets coded in vanilla JS (or a lightweight, bundled library)
• Instant Correct/Incorrect indication plus detailed rationale text for every option
• Responsive layout for text and images, with fallback styling for older e-readers
• All assets embedded and referenced with relative paths only

Deliverables:
1. Final .epub file ready for upload
2. Source folder with well-commented code and build script (if used)
3. Brief setup/readme so I can add future chapters following the same pattern

If this sounds like something you’ve done before—especially if you’ve shipped interactive EPUBs that pass strict offline tests—let’s talk.