Viewport <#document> at (0,0) content-size 800x600 children: not-inline BlockContainer at (0,0) content-size 800x600 [BFC] children: not-inline BlockContainer at (8,8) content-size 784x0 children: not-inline ViewportPaintable (Viewport<#document>) [0,0 800x600] PaintableWithLines (BlockContainer) [0,0 800x600] PaintableWithLines (BlockContainer) [8,8 784x0] SC for Viewport<#document> [0,0 800x600] [children: 1] (z-index: auto) SC for BlockContainer [0,0 800x600] [children: 0] (z-index: auto)