Viewport <#document> at (0,0) content-size 800x600 children: not-inline
  BlockContainer <html> at (0,0) content-size 800x34 [BFC] children: not-inline
    Box <body> at (8,8) content-size 784x18 flex-container(column) [FFC] children: not-inline
      BlockContainer <main> at (8,8) content-size 784x18 flex-item [BFC] children: inline
        frag 0 from TextNode start: 0, length: 13, rect: [8,8 153.984375x18] baseline: 13.796875
            "hmmMMMMmmmmmm"
        TextNode <#text>

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