Viewport <#document> at [0,0] [0+0+0 800 0+0+0] [0+0+0 600 0+0+0] children: not-inline
  BlockContainer <html> at [0,0] [0+0+0 800 0+0+0] [0+0+0 60 0+0+0] [BFC] children: not-inline
    BlockContainer <body> at [8,8] [8+0+0 784 0+0+8] [8+0+0 44 0+0+8] children: not-inline
      BlockContainer <button.btn.fixed-width> at [13,10] [0+1+4 190 4+1+584] [0+1+1 18 1+1+0] children: not-inline
        BlockContainer <(anonymous)> at [13,10] flex-container(column) [0+0+0 190 0+0+0] [0+0+0 18 0+0+0] [FFC] children: not-inline
          BlockContainer <(anonymous)> at [13,10] flex-item [0+0+0 190 0+0+0] [0+0+0 18 0+0+0] [BFC] children: inline
            frag 0 from TextNode start: 0, length: 11, rect: [60.53125,10 94.921875x18] baseline: 13.796875
                "200px width"
            TextNode <#text> (not painted)
      BlockContainer <button.btn> at [13,32] [0+1+4 324.671875 4+1+0] [0+1+1 18 1+1+0] children: not-inline
        BlockContainer <(anonymous)> at [13,32] flex-container(column) [0+0+0 324.671875 0+0+0] [0+0+0 18 0+0+0] [FFC] children: not-inline
          BlockContainer <(anonymous)> at [13,32] flex-item [0+0+0 324.671875 0+0+0] [0+0+0 18 0+0+0] [BFC] children: inline
            frag 0 from TextNode start: 0, length: 39, rect: [13,32 324.671875x18] baseline: 13.796875
                "auto width should behave as fit-content"
            TextNode <#text> (not painted)

ViewportPaintable (Viewport<#document>) [0,0 800x600]
  PaintableWithLines (BlockContainer<HTML>) [0,0 800x60]
    PaintableWithLines (BlockContainer<BODY>) [8,8 784x44]
      PaintableWithLines (BlockContainer<BUTTON>.btn.fixed-width) [8,8 200x22]
        PaintableWithLines (BlockContainer(anonymous)) [13,10 190x18]
          PaintableWithLines (BlockContainer(anonymous)) [13,10 190x18]
            TextPaintable (TextNode<#text>)
      PaintableWithLines (BlockContainer<BUTTON>.btn) [8,30 334.671875x22]
        PaintableWithLines (BlockContainer(anonymous)) [13,32 324.671875x18]
          PaintableWithLines (BlockContainer(anonymous)) [13,32 324.671875x18]
            TextPaintable (TextNode<#text>)

SC for Viewport<#document> [0,0 800x600] [children: 1] (z-index: auto)
 SC for BlockContainer<HTML> [0,0 800x60] [children: 0] (z-index: auto)
