{{ with .Params.series }}
  {{ $currentPage := $ }}
  {{ $series := index . 0 }}
  {{ $currentOrder := $.Params.series_order }}

  {{/* Get all posts in this series */}}
  {{ $seriesPosts := where $.Site.RegularPages "Params.series" "intersect" (slice $series) }}
  {{ $seriesPosts = sort $seriesPosts "Params.series_order" }}
  {{ $totalParts := len $seriesPosts }}

  {{ if gt $totalParts 1 }}
    <div class="series-box">
      <div class="series-header">
        <strong>{{ $series }}</strong>
        <span class="series-part">Part {{ $currentOrder }} of {{ $totalParts }}</span>
      </div>

      <nav class="series-nav">
        <ol class="series-list">
          {{ range $seriesPosts }}
            <li class="{{ if eq .RelPermalink $currentPage.RelPermalink }}current{{ end }}">
              {{ if eq .RelPermalink $currentPage.RelPermalink }}
                <strong>{{ .Title }}</strong>
              {{ else }}
                <a href="{{ .RelPermalink }}">{{ .Title }}</a>
              {{ end }}
            </li>
          {{ end }}
        </ol>
      </nav>

      <div class="series-navigation">
        {{/* Previous post */}}
        {{ $prevPost := "" }}
        {{ $nextPost := "" }}
        {{ $foundCurrent := false }}

        {{ range $seriesPosts }}
          {{ if $foundCurrent }}
            {{ if not $nextPost }}
              {{ $nextPost = . }}
            {{ end }}
          {{ else if eq .RelPermalink $currentPage.RelPermalink }}
            {{ $foundCurrent = true }}
          {{ else }}
            {{ $prevPost = . }}
          {{ end }}
        {{ end }}

        <div class="series-nav-links">
          {{ with $prevPost }}
            <a href="{{ .RelPermalink }}" class="series-prev">← Previous: {{ .Title }}</a>
          {{ else }}
            <span class="series-prev disabled">← Previous</span>
          {{ end }}

          {{ with $nextPost }}
            <a href="{{ .RelPermalink }}" class="series-next">Next: {{ .Title }} →</a>
          {{ else }}
            <span class="series-next disabled">Next →</span>
          {{ end }}
        </div>
      </div>
    </div>
  {{ end }}
{{ end }}