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+0 152 0+0+0] [BFC] children: not-inline
    BlockContainer <body> at [8,8] [8+0+0 784 0+0+8] [8+0+0 136 0+0+8] children: not-inline
      BlockContainer <details> at [68,68] [0+10+50 664 50+10+0] [0+10+50 16 50+10+0] children: not-inline
        ListItemBox <summary> at [68,68] [0+0+0 664 0+0+0] [0+0+0 16 0+0+0] children: inline
          frag 0 from ListItemMarkerBox start: 0, length: 0, rect: [68,68 13.84375x16] baseline: 12.796875
          frag 1 from TextNode start: 0, length: 5, rect: [81.84375,68 36.84375x16] baseline: 12.796875
              "hello"
          ListItemMarkerBox <(anonymous)> at [68,68] [0+0+0 13.84375 0+0+0] [0+0+0 16 0+0+0] [BFC] children: inline
            frag 0 from GeneratedTextNode start: 0, length: 2, rect: [68,68 13.84375x16] baseline: 12.796875
                "▸ "
            GeneratedTextNode <(anonymous)> (not painted)
          TextNode <#text> (not painted)
        BlockContainer <slot> at [68,84] [0+0+0 664 0+0+0] [0+0+0 0 0+0+0] children: not-inline

ViewportPaintable (Viewport<#document>) [0,0 800x600]
  PaintableWithLines (BlockContainer<HTML>) [0,0 800x152]
    PaintableWithLines (BlockContainer<BODY>) [8,8 784x136]
      PaintableWithLines (BlockContainer<DETAILS>) [8,8 784x136]
        PaintableWithLines (ListItemBox<SUMMARY>) [68,68 664x16]
          PaintableWithLines (ListItemMarkerBox(anonymous)) [68,68 13.84375x16]
        PaintableWithLines (BlockContainer<SLOT>) [68,84 664x0]

SC for Viewport<#document> [0,0 800x600] (z-index: auto)
 SC for BlockContainer<HTML> [0,0 800x152] (z-index: auto)
