Viewport <#document> at (0,0) content-size 800x600 children: not-inline
  BlockContainer <html> at (0,0) content-size 800x34 [BFC] children: not-inline
    BlockContainer <body> at (8,8) content-size 784x18 children: not-inline
      Box <div.container> at (8,8) content-size 784x18 flex-container(row) [FFC] children: not-inline
        BlockContainer <div> at (8,8) content-size 14.265625x18 flex-item [BFC] children: inline
          frag 0 from TextNode start: 0, length: 1, rect: [8,8 14.265625x18] baseline: 13.796875
              "A"
          TextNode <#text>

ViewportPaintable (Viewport<#document>) [0,0 800x600]
  PaintableWithLines (BlockContainer<HTML>) [0,0 800x34]
    PaintableWithLines (BlockContainer<BODY>) [8,8 784x18]
      PaintableBox (Box<DIV>.container) [8,8 784x18]
        PaintableWithLines (BlockContainer<DIV>) [8,8 14.265625x18]
          TextPaintable (TextNode<#text>)
