SalGnt/Travelogue ? reverse-engineered prompt

Build me a clean, minimal Jekyll blog theme that feels very focused on reading. I want a single column layout with a nice immersive look, responsive on mobile, and easy to use for long form posts.

The theme should support a sidebar menu with links to pages, an about page, an archive page, a custom 404 page, and a simple homepage that shows posts clearly. For each post, I want optional thumbnail images, optional full page background images that can change as the reader scrolls, and a next post link at the end. Put the post details like author, tags, and categories after the content, and let me hide tags or categories when I want.

Please also add optional share buttons and optional Disqus comments, both turned on from config. Make it easy to customize through front matter and the main config files. Keep the design polished, lightweight, and content first. If you need to check anything, look up the current Jekyll docs online.