Viewport <#document> at (0,0) content-size 800x600 children: not-inline
BlockContainer <html> at (0,0) content-size 800x600 [BFC] children: not-inline
BlockContainer <body> at (8,8) content-size 784x34 children: not-inline
BlockContainer <details> at (8,8) content-size 784x34 children: not-inline
ListItemBox <summary> at (32,8) content-size 760x17 children: inline
frag 0 from TextNode start: 0, length: 13, rect: [32,8 114.625x17] baseline: 13.296875
"I'm a summary"
TextNode <#text>
ListItemMarkerBox <(anonymous)> at (8,8) content-size 12x17 children: not-inline
BlockContainer <slot> at (8,25) content-size 784x17 children: inline
TextNode <#text>
TextNode <#text>
InlineNode <span>
frag 0 from TextNode start: 0, length: 10, rect: [8,25 82.3125x17] baseline: 13.296875
"I'm a node"
TextNode <#text>
TextNode <#text>
BlockContainer <(anonymous)> at (8,42) content-size 784x0 children: inline
TextNode <#text>
ViewportPaintable (Viewport<#document>) [0,0 800x600]
PaintableWithLines (BlockContainer<HTML>) [0,0 800x600]
PaintableWithLines (BlockContainer<BODY>) [8,8 784x34]
PaintableWithLines (BlockContainer<DETAILS>) [8,8 784x34]
PaintableWithLines (ListItemBox<SUMMARY>) [32,8 760x17]
TextPaintable (TextNode<#text>)
MarkerPaintable (ListItemMarkerBox(anonymous)) [8,8 12x17]
PaintableWithLines (BlockContainer<SLOT>) [8,25 784x17]
InlinePaintable (InlineNode<SPAN>)
TextPaintable (TextNode<#text>)
PaintableWithLines (BlockContainer(anonymous)) [8,42 784x0]