[css-transforms] description of rendering of elements

https://drafts.csswg.org/css-transforms/#3d-rendering-contexts
currently says:

  # The rendering of elements in a 3D rendering context is as
  # follows (numbers refer to items in CSS 2.1, Appendix E, Section
  # E.2 Painting Order):
  # 
  #  A. The background, borders and other box decorations of the
  #     establishing element are rendered (steps 1 and 2)
  #  B. The content and descendant elements without 3D transforms,
  #     ordered according to steps 3—7, are rendered into a plane at
  #     z=0 relative to to the establishing element.
  #  C. 3D-transformed elements are each rendered into their own
  #     plane, transformed by the accumulated 3D transformation
  #     matrix. 
  #  [...]

This should be clearer that the non-3D-transformed descendants of an
element with a 3D transform are included in (C) rather than included
in (B), as a literal reading of the text would suggest.

Likewise, it should be clear that 3D transformed descendants that
are in a different 3D rendering context are included within the
flattened plane for their nearest 3D ancestor that is in the 3D
rendering context, rather than in their own plane.

This might be best done by restructuring the text a bit.

-David

-- 
𝄞   L. David Baron                         http://dbaron.org/   𝄂
𝄢   Mozilla                          https://www.mozilla.org/   𝄂
             Before I built a wall I'd ask to know
             What I was walling in or walling out,
             And to whom I was like to give offense.
               - Robert Frost, Mending Wall (1914)