Modern Ebook Layout Design Needed

I have the manuscript and image assets ready; now I need a polished layout that blends text and visuals seamlessly. I’m after a modern, clean aesthetic—white space used intelligently, consistent typography, and images that sit naturally beside the copy without overwhelming it.

Please structure the file so it works flawlessly on the major ebook platforms (Kindle, Apple Books, EPUB-compatible readers) and looks equally good on tablets and phones.

Essential elements I want incorporated:
• Table of contents that auto-updates from the headings
• Clearly defined sections with hierarchy-driven headings

Deliver the final ebook in EPUB and MOBI, along with the source file you build in InDesign, Affinity Publisher, or a comparable tool. Once I import it, everything should render without manual tweaks.