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 32 0+0+0] [BFC] children: not-inline
    Box <body> at [8,8] flex-container(column) [8+0+0 784 0+0+8] [8+0+0 16 0+0+8] [FFC] children: not-inline
      BlockContainer <main> at [8,8] flex-item [0+0+0 784 0+0+0] [0+0+0 16 0+0+0] [BFC] children: inline
        frag 0 from TextNode start: 0, length: 13, rect: [8,8 153.984375x16] baseline: 12.796875
            "hmmMMMMmmmmmm"
        TextNode <#text> (not painted)

ViewportPaintable (Viewport<#document>) [0,0 800x600]
  PaintableWithLines (BlockContainer<HTML>) [0,0 800x32]
    Paintable (Box<BODY>) [8,8 784x16]
      PaintableWithLines (BlockContainer<MAIN>) [8,8 784x16]

SC for Viewport<#document> [0,0 800x600] (z-index: auto)
 SC for BlockContainer<HTML> [0,0 800x32] (z-index: auto)
