posts.js.coffee

$ ->

  $(window).scroll ->
    if $(window).width() > 640
      $widget = $(".sidebar-widget")
      $position = $widget.offset().top
      $breakPosition = $('.author-bio').offset().top
      if ($(window).scrollTop() > $('.post-header').height()) && ($position < $breakPosition)
        $widget.stop().animate marginTop: $(window).scrollTop() - $('header').height() - 155
      else
        $widget.stop().animate marginTop: 0