Viewport <#document> at (0,0) content-size 800x600 children: not-inline BlockContainer at (0,0) content-size 800x316 [BFC] children: not-inline BlockContainer at (8,8) content-size 784x300 children: not-inline BlockContainer at (13,10) content-size 290x296 children: not-inline BlockContainer <(anonymous)> at (13,10) content-size 290x296 flex-container(column) [FFC] children: not-inline BlockContainer <(anonymous)> at (13,149.5) content-size 290x17 flex-item [BFC] children: inline frag 0 from BlockContainer start: 0, length: 0, rect: [36.75,149.5 242.5x17] baseline: 13 BlockContainer at (36.75,149.5) content-size 242.5x17 inline-block [BFC] children: inline frag 0 from TextNode start: 0, length: 31, rect: [36.75,149.5 242.5x17] baseline: 13 "Should be located in the center" TextNode <#text> BlockContainer <(anonymous)> at (8,308) content-size 784x0 children: inline TextNode <#text> ViewportPaintable (Viewport<#document>) [0,0 800x600] PaintableWithLines (BlockContainer) [0,0 800x316] PaintableWithLines (BlockContainer) [8,8 784x300] PaintableWithLines (BlockContainer.btn) [8,8 300x300] PaintableWithLines (BlockContainer(anonymous)) [13,10 290x296] PaintableWithLines (BlockContainer(anonymous)) [13,149.5 290x17] PaintableWithLines (BlockContainer) [36.75,149.5 242.5x17] TextPaintable (TextNode<#text>) PaintableWithLines (BlockContainer(anonymous)) [8,308 784x0] SC for Viewport<#document> [0,0 800x600] [children: 1] (z-index: auto) SC for BlockContainer [0,0 800x316] [children: 0] (z-index: auto)