Is there any library to construct a render tree from html and css files?

I found hast-util-from-parse5 (https://github.com/syntax-tree/hast-util-from-parse5) can create AST (DOM tree) from html file, and CSSTree (https://github.com/csstree/csstree) can do the similar thing for CSS.
I want to get render tree which should have both html and css elements in the same tree. Is there any library to do that?
Thank you.