https://blog.tomayac.com/2021/01/24/ruby-html-footnotes/
<ruby> HTML footnotes
Jan 24, 2021 - The personal blog of Thomas Steiner
lt ruby gthtmlfootnotes
https://developer.chrome.com/blog/line-breakable-ruby
Line-breakable <ruby> and CSS ruby-align property | Blog | Chrome for Developers
Line-breakable ruby element and CSS ruby-align property
lt ruby gtlinebreakablecss