State of HTML/CSS 2020

Hi,
I'm writing an article about soon-to-be-supported html/css features. I only
know about the dialog element and the prefers-color-scheme media query. Are
there any other ones you would recoommend that I include?  It tried to
search the w3c specifications, but I found that many of the specs were very
technical or obscure, and not conducive to creating a useful article.
Additionally, what is the expected timeline for css nesting? I am truying
to judge whether or not to add that to my article. Please advice

-- 
 *Binyamin Green*
 443.803.9499
 binyaminagreen@gmail.com
 https://b3u.netlify.com