{#
  Lazy chunk placeholder contract (static export variant):
  - id="document-chunk-N" identifies the frame as a document chunk.
  - class="document-chunk-placeholder" marks an unloaded placeholder.
  - data-chunk-src/data-chunk-key point toc_chunk_navigation.js's static
    delivery path (loadStaticChunk()) at the generated .js file and the
    window.StrictDoc.chunks key it assigns - there is no FastAPI server to
    fetch a fragment route from, and fetch()/XHR to a sibling file is
    blocked under file://, so the chunk's HTML is delivered as a <script>
    instead (see document.py's DocumentHTMLGenerator._export_static_chunks).
  - data-node-mids maps every semantic node, including nodes
    omitted from TOC, to the frame that can load it.

  - node.css uses the placeholder class to reserve approximate
    scroll space until the chunk script loads.
  - toc_chunk_navigation.js observes placeholders by this class,
    validates the document-chunk-* id, eagerly preloads them near
    the viewport, and removes the class once the chunk has loaded.

  content_viewport_restoration.js is loaded for chunked static documents too
  (see document/index.jinja) and compensates the scroll position when a
  background-preloaded chunk above the reading position resolves from its
  estimated height to its real height; toc_chunk_navigation.js's
  loadStaticChunk() dispatches the synthetic events it listens for.
#}
<turbo-frame
  id="document-chunk-{{ chunk.index }}"
  class="document-chunk-placeholder"
  data-chunk-src="{{ view_object.static_chunk_relative_path(chunk) }}"
  data-chunk-key="{{ view_object.static_chunk_key(chunk) }}"
  style="--document-chunk-size: {{ chunk.size }};"
  data-node-mids="{{ chunk.node_mids | join(' ') }}"
  data-testid="document-chunk-placeholder"
></turbo-frame>