I like to include an inline TOC, which is another html file with links to the enteries
(Tools, TOC, Inline TOC)
That HTML file is edit-able if you want to tweak it
https://manual.calibre-ebook.com/edi...le-of-contents
You can create a template that will be used instead of the default
C:\Users\<userid>\AppData\Roaming\calibre\resource s\templates\inline_toc_styles.css
I'm sure there's instructions in the user manual about using the css but I always have a hard time finding things there