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 64 0+0+0] [BFC] children: not-inline
    BlockContainer <body> at [8,8] [8+0+0 784 0+0+8] [8+0+0 48 0+0+8] children: not-inline
      BlockContainer <(anonymous)> at [8,8] [0+0+0 784 0+0+0] [0+0+0 16 0+0+0] children: inline
        frag 0 from TextNode start: 0, length: 38, rect: [8,8 315.609375x16] baseline: 12.796875
            "-- There should be a 1em gap here: ---"
        TextNode <#text> (not painted)
      BlockContainer <p> at [8,40] [0+0+0 784 0+0+0] [16+0+0 0 0+0+16] children: not-inline
        BlockContainer <span> at [8,40] [0+0+0 784 0+0+0] [16+0+0 0 0+0+16] children: not-inline
      BlockContainer <(anonymous)> at [8,40] [0+0+0 784 0+0+0] [0+0+0 16 0+0+0] children: inline
        frag 0 from TextNode start: 1, length: 38, rect: [8,40 273.375x16] baseline: 12.796875
            "-- Gap End ---------------------------"
        TextNode <#text> (not painted)

ViewportPaintable (Viewport<#document>) [0,0 800x600]
  PaintableWithLines (BlockContainer<HTML>) [0,0 800x64]
    PaintableWithLines (BlockContainer<BODY>) [8,8 784x48]
      PaintableWithLines (BlockContainer(anonymous)) [8,8 784x16]
      PaintableWithLines (BlockContainer<P>) [8,40 784x0]
        PaintableWithLines (BlockContainer<SPAN>) [8,40 784x0]
      PaintableWithLines (BlockContainer(anonymous)) [8,40 784x16]

SC for Viewport<#document> [0,0 800x600] (z-index: auto)
 SC for BlockContainer<HTML> [0,0 800x64] (z-index: auto)
