Viewport <#document> at [0,0] [0+0+0 800 0+0+0] [0+0+0 600 0+0+0] [BFC] children: not-inline
  BlockContainer <html> at [0,0] [0+0+0 800 0+0+0] [0+0+0 116 0+0+0] [BFC] children: not-inline
    Box <body> at [8,8] flex-container(row) [8+0+0 400 0+0+392] [8+0+0 100 0+0+8] [FFC] children: not-inline
      Box <div.outer> at [8,8] flex-container(column) flex-item [0+0+0 200 0+0+0] [0+0+0 100 0+0+0] [FFC] children: not-inline
        BlockContainer <div.upper> at [8,8] flex-item [0+0+0 200 0+0+0] [0+0+0 200 0+0+0] [BFC] children: not-inline
          BlockContainer <div.spacer> at [8,8] [0+0+0 200 0+0+0] [0+0+0 200 0+0+0] children: not-inline
        BlockContainer <div.lower> at [8,208] flex-item [0+0+0 200 0+0+0] [0+0+0 18 0+0+0] [BFC] children: inline
          frag 0 from TextNode start: 0, length: 3, rect: [8,208 26.953125x18] baseline: 13.796875
              "whf"
          TextNode <#text> (not painted)

ViewportPaintable (Viewport<#document>) [0,0 800x600]
  PaintableWithLines (BlockContainer<HTML>) [0,0 800x116]
    PaintableBox (Box<BODY>) [8,8 400x100]
      PaintableBox (Box<DIV>.outer) [8,8 200x100]
        PaintableWithLines (BlockContainer<DIV>.upper) [8,8 200x200]
          PaintableWithLines (BlockContainer<DIV>.spacer) [8,8 200x200]
        PaintableWithLines (BlockContainer<DIV>.lower) [8,208 200x18]
          TextPaintable (TextNode<#text>)

SC for Viewport<#document> [0,0 800x600] [children: 1] (z-index: auto)
 SC for BlockContainer<HTML> [0,0 800x116] [children: 0] (z-index: auto)
