anchor.diff:      event.target.isContentEditable
     )
   
  -onTogglingClick = (callback) ->
  +keydownEventIsSignificant = (event) ->
  +  not (
  +    event.defaultPrevented or
  +    (event.keyCode != 32 and event.keyCode != 13) or
  +    event.altKey or
  +    event.ctrlKey or
  +    event.metaKey or
  +    event.shiftKey or
  +    event.target.isContentEditable
  +  )
  +
  +onTogglingTrigger = (callback) ->
     addEventListener "click", (event) ->
       if clickEventIsSignificant(event)
         if element = findClosestElementWithTagName(event.target, "SUMMARY")
           if element.parentElement?.tagName is "DETAILS"
             callback(element.parentElement)
  +  , false
  +
  +  addEventListener "keydown", (event) ->
  +    if keydownEventIsSignificant(event)
  +      if element = findClosestElementWithTagName(event.target, "SUMMARY")
  +        if element.parentElement?.tagName is "DETAILS"
  +          callback(element.parentElement)
  +          # Prevent pagedown from space key
  +          event.preventDefault()
     , false
   
   findClosestElementWithTagName = do ->
  
positive.code:   polyfillStyles()
    polyfillProperties()
    polyfillToggle()
  
  if support.element and not support.toggleEvent
    polyfillToggleEvent()
  
negative.code: 
      observer.observe(document.documentElement, attributes: true, subtree: true)
    else
      onTogglingTrigger (element) ->
        open = element.getAttribute("open")
        setTimeout ->
          unless element.getAttribute("open") is open
  