gistfile1.coffee

            cssMonitor: ->
                @selectors = []
                for ss in document.styleSheets
                    for rule in ss.cssRules when rule.selectorText
                        @selectors.push(rule.selectorText)
                @selectors.sort()

                isUnused = (sel) ->
                    try
                        $(sel).length == 0
                    catch
                        return true
                count = @selectors.length

                setInterval((=>
                    @selectors = @selectors.filter(isUnused)
                    if count isnt @selectors.length
                        count = @selectors.length
                        console.warn('unused selectors', count)
                ), 1000)

            getUnusedSelectors: -> @selectors