props
  previousHref?: string
  previousTitle?: string
  nextHref?: string
  nextTitle?: string
nav.article-nav
  if previousHref
    a.article-nav-item.prev(href=previousHref)
      div.nav-arrow Previous
      span.article-title= previousTitle
  if nextHref
    a.article-nav-item.next(href=nextHref)
      div.nav-arrow Next
      span.article-title= nextTitle