Custom list indent width with indentation guides

I’d like live preview (and source view) to present nested list indented at least as deeply as reading view, preferably providing a setting for both that can be set to any custom amount. All this, while preserving indentation lines, that have been recently added to the core app.

There have been numerous requests for this, this one being the most recent I found. However these all broke eventually. The answer accepted to this last one was a flawed hack that became more obsolete with v0.14.

Even if this doesn’t make it into core, I’d be relieved to have a workable, up to date custom CSS snippet that addresses all the concerns listed above.