Posted by Alexander Schwartz on Oct 02, 2019; 6:48am
URL: https://discuss.asciidoctor.org/Multilevel-nested-ordered-lists-numbering-tp7170p7175.html

For the HTML output you also have the choice of adding custom CSS.

I've answered a similar question on StackOverflow. Maybe this is close to what you are looking for: https://stackoverflow.com/questions/49189563/sublist-numbering-in-asciidoc/57244921#57244921

You can add CSS as either pass through content, or as a custom stylesheet that replaces the standard asciidoctor CSS stylesheet. See https://asciidoctor.org/docs/user-manual/#applying-a-theme for more information.