- bg_image = (attr? 'title-slide-background-image') ? (image_uri(attr 'title-slide-background-image')) : nil
- bg_video = (attr? 'title-slide-background-video') ? (media_uri(attr 'title-slide-background-video')) : nil
section.title(class = role
  data-state='title'
  data-transition=(attr 'title-slide-transition')
  data-transition-speed=(attr 'title-slide-transition-speed')
  data-background=(attr 'title-slide-background')
  data-background-size=(attr 'title-slide-background-size')
  data-background-image=bg_image
  data-background-video=bg_video
  data-background-video-loop=(attr 'title-slide-background-video-loop')
  data-background-video-muted=(attr 'title-slide-background-video-muted')
  data-background-opacity=(attr 'title-slide-background-opacity')
  data-background-iframe=(attr 'title-slide-background-iframe')
  data-background-color=(attr 'title-slide-background-color')
  data-background-repeat=(attr 'title-slide-background-repeat')
  data-background-position=(attr 'title-slide-background-position')
  data-background-transition=(attr 'title-slide-background-transition'))
  - if (_title_obj = doctitle partition: true, use_fallback: true).subtitle?
    h1=slice_text _title_obj.title, (_slice = header.option? :slice)
    h2=slice_text _title_obj.subtitle, _slice
  - else
    h1=@header.title
  - preamble = @document.find_by context: :preamble
  - unless preamble.nil? or preamble.length == 0
    div.preamble=preamble.pop.content
  - unless author.nil?
    p.author: small=author