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] [0+0+0 800 0+0+0] [0+0+0 600 0+0+0] [BFC] children: not-inline BlockContainer at [8,8] [8+0+0 784 0+0+8] [8+0+0 584 0+0+8] children: not-inline ViewportPaintable (Viewport<#document>) [0,0 800x600] PaintableWithLines (BlockContainer) [0,0 800x600] PaintableWithLines (BlockContainer) [8,8 784x584] SC for Viewport<#document> [0,0 800x600] [children: 1] (z-index: auto) SC for BlockContainer [0,0 800x600] [children: 0] (z-index: auto)