Viewport <#document> at [0,0] [0+0+0 800 0+0+0] [0+0+0 600 0+0+0] [BFC] children: not-inline BlockContainer at [0,0] positioned [0+0+0 500 0+0+300] [0+0+0 300 0+0+0] [BFC] children: not-inline Box at [0,0] positioned flex-container(row) [0+0+0 500 0+0+0] [0+0+0 55 0+0+0] [FFC] children: not-inline BlockContainer
at [0,0] positioned flex-item [0+0+0 500 0+0+0] [0+0+0 55 0+0+0] [BFC] children: not-inline BlockContainer
at [0,0] [0+0+0 250 0+0+250] [0+0+0 55 0+0+0] children: inline TextNode <#text> (not painted) ViewportPaintable (Viewport<#document>) [0,0 800x600] PaintableWithLines (BlockContainer) [0,0 500x300] PaintableBox (Box) [0,0 500x55] PaintableWithLines (BlockContainer
) [0,0 500x55] PaintableWithLines (BlockContainer
) [0,0 250x55] SC for Viewport<#document> [0,0 800x600] [children: 1] (z-index: auto) SC for BlockContainer [0,0 500x300] [children: 0] (z-index: auto)