Viewport <#document> at (0,0) content-size 800x600 children: not-inline
  BlockContainer <html> at (0,0) content-size 800x208 [BFC] children: not-inline
    BlockContainer <body> at (8,8) content-size 784x0 children: not-inline
      BlockContainer <div.box> at (108,108) content-size 100x0 floating [BFC] children: not-inline

ViewportPaintable (Viewport<#document>) [0,0 800x600]
  PaintableWithLines (BlockContainer<HTML>) [0,0 800x208]
    PaintableWithLines (BlockContainer<BODY>) [8,8 784x0] overflow: [8,8 300x200]
      PaintableWithLines (BlockContainer<DIV>.box) [8,8 300x200]
