message: Codifies page breakout styling
diff: max-width layout-narrow-width
  padding 1em
  +.PageNarrowBreakout
  + margin-left -4em !important
  + margin-right -4em !important
  +
  + +below(layout-narrow-width + (8 * font-size-root))
  + margin-left inherit !important
  + margin-right inherit !important
  +
  .Section
  @extend .Page
  collapsed-margins(1em)
  