diff --git a/frontend/src/routes/documents/[id]/+page.svelte b/frontend/src/routes/documents/[id]/+page.svelte
index 1016377..e6f8746 100644
--- a/frontend/src/routes/documents/[id]/+page.svelte
+++ b/frontend/src/routes/documents/[id]/+page.svelte
@@ -1,19 +1,17 @@
 <script>
-  // Phase E.2 — detail 페이지 inline 편집.
-  // 기존 read-only 메타 패널(L138–201)을 editors/* 스택으로 교체.
-  // + E.3 관련 문서 stub, + 헤더 affordance row.
+  // 문서 상세 /documents/[id] — D3 절 구조 탐색기 (확정 시안 충실 구현).
+  // 레이아웃: [좌 절 트리][중 절 집중 뷰][우 슬림 전역 인사이트 레일]. 절 없으면 fallback(본문+레일).
+  // 절 본문 = md_content 를 char_start 로 슬라이스. 기존 편집/필기/인접네비/회독은 보존(관리·정보 접이).
   import { onMount } from 'svelte';
   import { page } from '$app/stores';
   import { goto } from '$app/navigation';
   import { api, getAccessToken } from '$lib/api';
   import { isMdSuccess } from '$lib/utils/mdStatus';
-  import { resolveAnchorMap } from '$lib/utils/resolveAnchorMap';
   import { addToast } from '$lib/stores/toast';
   import { marked } from 'marked';
   import DOMPurify from 'dompurify';
   import { ExternalLink, Download, Link2, FileText, PenLine, X, ChevronLeft, ChevronRight, Check } from 'lucide-svelte';
   import Button from '$lib/components/ui/Button.svelte';
-  import Card from '$lib/components/ui/Card.svelte';
   import EmptyState from '$lib/components/ui/EmptyState.svelte';
   import Skeleton from '$lib/components/ui/Skeleton.svelte';
   import HandwriteCanvas from '$lib/components/HandwriteCanvas.svelte';
@@ -27,13 +25,13 @@
   import ProcessingStatusView from '$lib/components/editors/ProcessingStatusView.svelte';
   import LibraryPathEditor from '$lib/components/editors/LibraryPathEditor.svelte';
   import DocumentDangerZone from '$lib/components/editors/DocumentDangerZone.svelte';
-  import AnalysisPanel from '$lib/components/AnalysisPanel.svelte';
   import ReadCounter from '$lib/components/ReadCounter.svelte';
-  import SectionOutline from '$lib/components/SectionOutline.svelte';
+  import { cleanHeading, pathSegments, sectionTypeLabel } from '$lib/utils/headingPath';
+  import { domainLabel } from '$lib/utils/domainSlug';
 
   marked.use({ mangle: false, headerIds: false });
   function renderMd(text) {
-    return DOMPurify.sanitize(marked(text), {
+    return DOMPurify.sanitize(marked(text || ''), {
       USE_PROFILES: { html: true },
       FORBID_TAGS: ['style', 'script'],
       FORBID_ATTR: ['onerror', 'onclick'],
@@ -43,52 +41,36 @@
 
   let doc = $state(null);
   let loading = $state(true);
-  let error = $state(null); // 'not_found' | 'network' | null
-  let rawMarkdown = $state(''); // fallback: extracted_text 없을 때 원본 .md
-
+  let error = $state(null);
+  let rawMarkdown = $state('');
   let docId = $derived($page.params.id);
 
-  // 손글씨 노트 (자료별 1:1) — "필기" 토글 시 사이드 캔버스 띄움.
+  // 손글씨 노트
   let noteOpen = $state(false);
-  let noteStrokes = $state(null); // { version, strokes }
+  let noteStrokes = $state(null);
   let noteLoaded = $state(false);
   async function ensureNoteLoaded() {
     if (noteLoaded) return;
     try {
       const r = await api(`/documents/${docId}/note`);
       noteStrokes = r.strokes_json && r.strokes_json.strokes ? r.strokes_json : { version: 1, strokes: [] };
-    } catch {
-      noteStrokes = { version: 1, strokes: [] };
-    }
+    } catch { noteStrokes = { version: 1, strokes: [] }; }
     noteLoaded = true;
   }
   async function saveNote(strokesJson) {
-    try {
-      await api(`/documents/${docId}/note`, {
-        method: 'PUT',
-        body: JSON.stringify({ strokes_json: strokesJson }),
-      });
-    } catch (err) {
-      console.warn('필기 저장 실패', err);
-    }
-  }
-  async function toggleNote() {
-    if (!noteOpen) await ensureNoteLoaded();
-    noteOpen = !noteOpen;
+    try { await api(`/documents/${docId}/note`, { method: 'PUT', body: JSON.stringify({ strokes_json: strokesJson }) }); }
+    catch (err) { console.warn('필기 저장 실패', err); }
   }
+  async function toggleNote() { if (!noteOpen) await ensureNoteLoaded(); noteOpen = !noteOpen; }
 
-  // 인접 자료 (같은 library_path 내 이전/다음) — 학습 흐름 네비게이션
+  // 인접 자료 (학습 흐름)
   let neighbors = $state({ prev: null, next: null });
   async function loadNeighbors() {
-    try {
-      neighbors = await api(`/documents/${docId}/library-neighbors`);
-    } catch {
-      neighbors = { prev: null, next: null };
-    }
+    try { neighbors = await api(`/documents/${docId}/library-neighbors`); }
+    catch { neighbors = { prev: null, next: null }; }
   }
 
-  // 절(hier section) 목차 — 본문 로드와 독립, 실패(404 포함) 무해.
-  // reqId guard: 문서 전환 race 시 stale 결과가 새 문서에 붙지 않게.
+  // 절(section) 목차
   let sections = $state([]);
   let hasSections = $derived(sections.length > 0);
   async function loadSections() {
@@ -97,22 +79,14 @@
       const r = await api(`/documents/${reqId}/sections`);
       if (reqId === docId) sections = r?.sections ?? [];
     } catch {
-      if (reqId === docId) sections = []; // Phase 1 미배포 시 404 → 목차 숨김(graceful)
+      if (reqId === docId) sections = [];
     }
   }
 
-  // "1회독 완료 + 다음 자료로" 한 번에
   async function readAndGoNext() {
-    try {
-      await api(`/documents/${docId}/read`, { method: 'POST' });
-      addToast('success', '1회독 완료');
-    } catch (err) {
-      addToast('error', err?.detail || '회독 기록 실패');
-      return;
-    }
-    if (neighbors.next) {
-      goto(`/documents/${neighbors.next.id}`);
-    }
+    try { await api(`/documents/${docId}/read`, { method: 'POST' }); addToast('success', '1회독 완료'); }
+    catch (err) { addToast('error', err?.detail || '회독 기록 실패'); return; }
+    if (neighbors.next) goto(`/documents/${neighbors.next.id}`);
   }
 
   onMount(async () => {
@@ -123,16 +97,11 @@
         try {
           const resp = await fetch(`/api/documents/${docId}/file?token=${getAccessToken()}`);
           if (resp.ok) rawMarkdown = await resp.text();
-        } catch (e) {
-          rawMarkdown = '';
-        }
+        } catch { rawMarkdown = ''; }
       }
     } catch (err) {
       error = err?.status === 404 ? 'not_found' : 'network';
-    } finally {
-      loading = false;
-    }
-    // 자료실 자료면 인접 자료 미리 fetch (학습 흐름 네비)
+    } finally { loading = false; }
     if (doc && doc.category === 'library') loadNeighbors();
     if (doc) loadSections();
   });
@@ -140,67 +109,17 @@
   let viewerType = $derived(
     doc ? (doc.source_channel === 'news' ? 'article' : getViewerType(doc.file_format)) : 'none'
   );
+  let canShowMarkdown = $derived(!!(isMdSuccess(doc?.md_status) && doc?.md_content?.trim()));
+  // D3 절 집중 뷰 조건: 절 + 마크다운 본문 둘 다 있을 때. 아니면 fallback(본문/뷰어 + 레일).
+  let useSectionView = $derived(hasSections && canShowMarkdown && !!doc?.md_content);
 
-  // PDF 분기 전용: marker_worker 가 만든 canonical markdown 이 있으면 기본으로 그것을 보여줌.
-  // Phase 1B 산출물의 95% 가 PDF 라 1D pilot 평가가 실사용 화면 기반이 되도록 markdown-first.
-  // 사용자가 "PDF 원본" 토글하면 iframe. lastDocId 로 문서 전환만 감지해서 사용자 토글이
-  // reactive cycle 에 덮이지 않도록 보호.
-  let pdfViewMode = $state('markdown'); // 'markdown' | 'pdf'
+  // PDF 폴백 토글
+  let pdfViewMode = $state('markdown');
   let lastDocId = $state(null);
-  let canShowMarkdown = $derived(
-    !!(isMdSuccess(doc?.md_status) && doc?.md_content?.trim())
-  );
-
   $effect(() => {
     if (!doc) return;
-    if (doc.id !== lastDocId) {
-      lastDocId = doc.id;
-      pdfViewMode = canShowMarkdown ? 'markdown' : 'pdf';
-    }
-    // 같은 문서 안에서 markdown 이 사라지면 (success → failed 재처리 등) PDF 로 보호.
-    if (!canShowMarkdown && pdfViewMode === 'markdown') {
-      pdfViewMode = 'pdf';
-    }
-  });
-
-  // ── 개요 점프 (경로 B: BE char_start primary + string-match 폴백) ──
-  // 이 사이트는 항상 md_content basis(canShowMarkdown && doc.md_content) → trustBE=true.
-  // BE char_start 가 있으면 채택, 비면(non-PASS/미백필) resolveAnchorMap 내부에서 buildAnchorMap 로 폴백.
-  let anchorMap = $derived(
-    hasSections && canShowMarkdown && doc?.md_content
-      ? resolveAnchorMap(doc.md_content, sections, { trustBE: true }).anchors
-      : {}
-  );
-  let activeKey = $state(null);
-  function jumpToSection(chunkId) {
-    const el = document.getElementById(`sec-${chunkId}`);
-    if (el) el.scrollIntoView({ behavior: 'smooth', block: 'start' });
-  }
-  // scroll-spy: 화면 상단(120px)을 지난 마지막 .md-anchor = 현재 절. [id] 는 window 스크롤.
-  $effect(() => {
-    void anchorMap; // 문서/섹션 변화 시 재바인딩
-    if (typeof window === 'undefined') return;
-    let raf = 0;
-    const onScroll = () => {
-      if (raf) return;
-      raf = requestAnimationFrame(() => {
-        raf = 0;
-        let cur = null;
-        document.querySelectorAll('.md-anchor').forEach((a) => {
-          if (a.getBoundingClientRect().top <= 120) cur = a;
-        });
-        if (cur) {
-          const m = cur.id.match(/^sec-(\d+)$/);
-          if (m) activeKey = Number(m[1]);
-        }
-      });
-    };
-    window.addEventListener('scroll', onScroll, { passive: true });
-    onScroll();
-    return () => {
-      window.removeEventListener('scroll', onScroll);
-      if (raf) cancelAnimationFrame(raf);
-    };
+    if (doc.id !== lastDocId) { lastDocId = doc.id; pdfViewMode = canShowMarkdown ? 'markdown' : 'pdf'; }
+    if (!canShowMarkdown && pdfViewMode === 'markdown') pdfViewMode = 'pdf';
   });
 
   function getViewerType(format) {
@@ -212,30 +131,197 @@
     return 'unsupported';
   }
 
-  // E.2 affordance row 핸들러
+  // ── 절 집중 뷰 상태 ──
+  let selectedSectionId = $state(null);
+  $effect(() => {
+    // 문서/섹션 로드 시 첫 절 선택. 선택이 현재 섹션집합에 없으면 첫 절로.
+    if (sections.length && !sections.some((s) => s.chunk_id === selectedSectionId)) {
+      selectedSectionId = sections[0].chunk_id;
+    }
+  });
+  let selectedSection = $derived(sections.find((s) => s.chunk_id === selectedSectionId) ?? sections[0] ?? null);
+  let selIdx = $derived(sections.findIndex((s) => s.chunk_id === selectedSection?.chunk_id));
+  // char_start 정렬 — 절 본문 슬라이스용
+  let sortedSecs = $derived(
+    [...sections].filter((s) => s.char_start != null).sort((a, b) => a.char_start - b.char_start)
+  );
+  function sectionBodyHtml(sec) {
+    if (!doc?.md_content || !sec || sec.char_start == null) return '';
+    const idx = sortedSecs.findIndex((s) => s.chunk_id === sec.chunk_id);
+    const start = sec.char_start;
+    const end = idx >= 0 && idx + 1 < sortedSecs.length ? sortedSecs[idx + 1].char_start : doc.md_content.length;
+    return renderMd(doc.md_content.slice(start, end));
+  }
+  let selectedBodyHtml = $derived(sectionBodyHtml(selectedSection));
+
+  const TYPE_META = {
+    definition: { label: '정의', color: '#2f7d8f' },
+    procedure: { label: '절차', color: '#4f8a6b' },
+    requirement: { label: '요건', color: '#b5840a' },
+  };
+  function typeMeta(t) { return TYPE_META[t] ?? { label: sectionTypeLabel(t) || '', color: '#9aa090' }; }
+  function confColor(c) { return c == null ? '#9aa090' : c < 0.6 ? '#b5840a' : '#1f9d6b'; }
+  function isLowConf(c) { return c != null && c < 0.5; }
+  function secTitle(s) { return cleanHeading(s.section_title) || pathSegments(s.heading_path).at(-1) || '(제목 없음)'; }
+  function secDepth(s) { return Math.max(0, (s.level ?? 1) - 1); }
+  function selectSection(id) { selectedSectionId = id; }
+
+  // 추출 품질 요약(있으면)
+  let quality = $derived(doc?.md_extraction_quality?.metrics ?? doc?.md_extraction_quality ?? null);
+
+  // 헤더/affordance
   function copyLink() {
     const url = `${window.location.origin}/documents/${docId}`;
-    navigator.clipboard
-      .writeText(url)
-      .then(() => addToast('success', '링크 복사됨'))
-      .catch(() => addToast('error', '복사 실패'));
-  }
-
-  function downloadOriginal() {
-    window.open(`/api/documents/${docId}/file?token=${getAccessToken()}&download=true`);
-  }
-
-  function downloadPdf() {
-    window.open(`/api/documents/${docId}/preview?token=${getAccessToken()}&download=true`);
-  }
-
-  function handleDocDelete() {
-    addToast('success', '문서가 삭제되어 목록으로 이동합니다.');
-    goto('/documents');
+    navigator.clipboard.writeText(url).then(() => addToast('success', '링크 복사됨')).catch(() => addToast('error', '복사 실패'));
   }
+  function downloadOriginal() { window.open(`/api/documents/${docId}/file?token=${getAccessToken()}&download=true`); }
+  function handleDocDelete() { addToast('success', '문서가 삭제되어 목록으로 이동합니다.'); goto('/documents'); }
 </script>
 
-<div class="p-4 lg:p-6">
+<!-- ════ 절 트리 (좌) ════ -->
+{#snippet treeNav()}
+  <div class="text-xs">
+    <div class="flex items-center justify-between mb-2">
+      <span class="text-[11px] font-bold text-dim uppercase tracking-wide">절 구조</span>
+      <span class="text-faint text-[11px]">{sections.length}절</span>
+    </div>
+    <!-- 유형 범례 -->
+    <div class="flex items-center gap-3 px-1 pb-2 mb-1 border-b border-default text-[10px] text-dim">
+      <span class="inline-flex items-center gap-1"><span class="w-2 h-2 rounded-sm" style="background:#2f7d8f"></span>정의</span>
+      <span class="inline-flex items-center gap-1"><span class="w-2 h-2 rounded-sm" style="background:#4f8a6b"></span>절차</span>
+      <span class="inline-flex items-center gap-1"><span class="w-2 h-2 rounded-sm" style="background:#b5840a"></span>요건</span>
+    </div>
+    <ul class="space-y-0.5">
+      {#each sections as s (s.chunk_id)}
+        {@const tm = typeMeta(s.section_type)}
+        {@const active = s.chunk_id === selectedSection?.chunk_id}
+        {@const low = isLowConf(s.confidence)}
+        <li>
+          <button type="button" onclick={() => selectSection(s.chunk_id)} aria-current={active ? 'true' : undefined}
+            style="padding-left:{8 + secDepth(s) * 13}px"
+            class="w-full text-left pr-2 py-1.5 rounded-md flex items-center gap-2 transition-colors border border-transparent
+              {active ? 'bg-surface-active text-text border-accent/40 font-semibold' : 'text-dim hover:bg-surface-hover hover:text-text'}
+              {secDepth(s) > 0 ? 'text-[11px]' : 'text-xs'}">
+            <span class="w-2 h-2 rounded-sm shrink-0" style="background:{tm.color}"></span>
+            <span class="flex-1 min-w-0 truncate leading-snug">{secTitle(s)}</span>
+            {#if low}
+              <span class="shrink-0 w-3.5 h-3.5 rounded-full border border-warning text-warning text-[9px] font-extrabold flex items-center justify-center" title="저신뢰 — 추출 불완전">!</span>
+            {:else}
+              <span class="shrink-0 w-1.5 h-1.5 rounded-full" style="background:{confColor(s.confidence)}" title="신뢰도 {s.confidence != null ? s.confidence.toFixed(2) : '—'}"></span>
+            {/if}
+          </button>
+        </li>
+      {/each}
+    </ul>
+    {#if quality}
+      <div class="mt-3 pt-2 border-t border-default text-[10px] text-faint leading-relaxed">
+        추출 품질
+        {#if quality.headings != null}· 제목 {quality.headings}{/if}
+        {#if quality.tables != null}· 표 {quality.tables}{/if}
+        {#if quality.images != null}· 이미지 {quality.images}{/if}
+      </div>
+    {/if}
+  </div>
+{/snippet}
+
+<!-- ════ 슬림 전역 인사이트 레일 (우) ════ -->
+{#snippet rail()}
+  <div class="space-y-3 text-xs">
+    <!-- TL;DR -->
+    {#if doc.ai_tldr || doc.ai_summary}
+      <div class="bg-surface border border-default rounded-card p-3.5">
+        <div class="text-[10px] font-bold text-warning uppercase tracking-wide mb-1.5">TL;DR</div>
+        <p class="text-text leading-relaxed">{doc.ai_tldr || doc.ai_summary}</p>
+      </div>
+    {/if}
+    <!-- 핵심점 -->
+    {#if doc.ai_bullets && doc.ai_bullets.length}
+      <div class="bg-surface border border-default rounded-card p-3.5">
+        <div class="text-[10px] font-bold text-dim uppercase tracking-wide mb-2">핵심점</div>
+        <ul class="space-y-1.5">
+          {#each doc.ai_bullets as b}
+            <li class="flex gap-1.5 text-text leading-relaxed"><span class="text-accent mt-px">·</span><span class="flex-1 min-w-0">{b}</span></li>
+          {/each}
+        </ul>
+      </div>
+    {/if}
+    <!-- 심층 -->
+    {#if doc.ai_detail_summary}
+      <div class="bg-surface border border-default rounded-card p-3.5">
+        <div class="flex items-center gap-2 mb-1.5">
+          <span class="text-[10px] font-bold text-dim uppercase tracking-wide">심층</span>
+          {#if doc.ai_analysis_tier === 'deep'}<span class="text-[9px] font-bold rounded px-1.5 py-px" style="background:#e3ebdf;color:#3d7256">DEEP</span>{/if}
+        </div>
+        <p class="text-dim leading-relaxed whitespace-pre-line">{doc.ai_detail_summary}</p>
+      </div>
+    {/if}
+    <!-- 불일치 -->
+    {#if doc.ai_inconsistencies && doc.ai_inconsistencies.length}
+      <div class="bg-surface border border-warning/50 rounded-card p-3.5">
+        <div class="text-[10px] font-bold text-warning uppercase tracking-wide mb-1.5">불일치 {doc.ai_inconsistencies.length}</div>
+        <ul class="space-y-1">
+          {#each doc.ai_inconsistencies as inc}
+            <li class="text-text leading-relaxed">· {typeof inc === 'string' ? inc : inc.desc || inc.kind}</li>
+          {/each}
+        </ul>
+      </div>
+    {/if}
+    <!-- 분류 -->
+    {#if doc.ai_domain}
+      <div class="bg-surface border border-default rounded-card p-3.5">
+        <div class="text-[10px] font-bold text-dim uppercase tracking-wide mb-1.5">분류</div>
+        <div class="text-text leading-relaxed">
+          <strong>{domainLabel(doc.ai_domain)}</strong>{#if doc.ai_sub_group} · {doc.ai_sub_group}{/if}
+          <div class="flex items-center gap-2 mt-1.5">
+            {#if doc.ai_confidence != null}<span class="text-success font-bold">신뢰도 {doc.ai_confidence.toFixed(2)}</span>{/if}
+            {#if doc.ai_analysis_tier}<span class="text-[9px] font-bold rounded px-1.5 py-px" style="background:#e3ebdf;color:#3d7256">{doc.ai_analysis_tier}</span>{/if}
+          </div>
+        </div>
+      </div>
+    {/if}
+    <!-- 태그 -->
+    {#if doc.ai_tags && doc.ai_tags.length}
+      <div class="bg-surface border border-default rounded-card p-3.5">
+        <div class="text-[10px] font-bold text-dim uppercase tracking-wide mb-2">태그</div>
+        <div class="flex flex-wrap gap-1.5">
+          {#each doc.ai_tags as t}<span class="text-[10.5px] text-accent-hover bg-accent/12 rounded-full px-2.5 py-0.5">{t}</span>{/each}
+        </div>
+      </div>
+    {/if}
+    <!-- 관련 문서 (v1 자리) -->
+    <div class="bg-surface border border-default rounded-card p-3.5">
+      <div class="text-[10px] font-bold text-dim uppercase tracking-wide mb-1.5">관련 문서</div>
+      <p class="text-faint leading-relaxed text-[11px]">벡터 유사도 기반 — 준비 중</p>
+    </div>
+    <!-- 정보 (접이) -->
+    <details class="bg-surface border border-default rounded-card overflow-hidden group">
+      <summary class="cursor-pointer list-none flex items-center justify-between px-3.5 py-2.5 text-[10px] font-bold text-dim uppercase tracking-wide select-none">
+        <span>문서 정보</span><ChevronRight size={13} class="transition-transform group-open:rotate-90 text-faint" />
+      </summary>
+      <div class="px-3.5 pb-3.5 space-y-3">
+        {#if doc.category === 'library'}<ReadCounter documentId={doc.id} initialCount={doc.read_count ?? 0} initialLastReadAt={doc.last_read_at ?? null} />{/if}
+        <FileInfoView {doc} />
+        <ProcessingStatusView {doc} />
+      </div>
+    </details>
+    <!-- 관리 (접이) -->
+    <details class="bg-surface border border-default rounded-card overflow-hidden group">
+      <summary class="cursor-pointer list-none flex items-center justify-between px-3.5 py-2.5 text-[10px] font-bold text-dim uppercase tracking-wide select-none">
+        <span>관리 · 분류 편집</span><ChevronRight size={13} class="transition-transform group-open:rotate-90 text-faint" />
+      </summary>
+      <div class="px-3.5 pb-3.5 space-y-3">
+        <AIClassificationEditor {doc} />
+        <LibraryPathEditor {doc} />
+        <NoteEditor {doc} />
+        <EditUrlEditor {doc} />
+        <TagsEditor {doc} />
+        <div class="pt-2 border-t border-default"><DocumentDangerZone {doc} ondelete={handleDocDelete} /></div>
+      </div>
+    </details>
+  </div>
+{/snippet}
+
+<div class="p-4 lg:p-6 max-w-[1360px] mx-auto">
   <!-- breadcrumb -->
   <div class="flex items-center gap-2 text-sm mb-4 text-dim">
     <a href="/documents" class="hover:text-text">문서</a>
@@ -244,320 +330,191 @@
   </div>
 
   {#if loading}
-    <div class="max-w-6xl mx-auto">
-      <Skeleton h="h-96" rounded="card" />
-    </div>
+    <Skeleton h="h-96" rounded="card" />
   {:else if error === 'not_found'}
-    <EmptyState
-      icon={FileText}
-      title="문서를 찾을 수 없습니다"
-      description="삭제되었거나 접근 권한이 없을 수 있습니다."
-    >
+    <EmptyState icon={FileText} title="문서를 찾을 수 없습니다" description="삭제되었거나 접근 권한이 없을 수 있습니다.">
       <Button variant="ghost" size="sm" href="/documents">목록으로 돌아가기</Button>
     </EmptyState>
   {:else if error === 'network'}
-    <EmptyState
-      icon={FileText}
-      title="문서를 불러올 수 없습니다"
-      description="네트워크 오류가 발생했습니다."
-    >
+    <EmptyState icon={FileText} title="문서를 불러올 수 없습니다" description="네트워크 오류가 발생했습니다.">
       <Button variant="secondary" size="sm" onclick={() => location.reload()}>다시 시도</Button>
     </EmptyState>
   {:else if doc}
-    <div class="mx-auto grid grid-cols-1 gap-6 {hasSections ? 'max-w-7xl xl:grid-cols-[18rem_minmax(0,1fr)_20rem]' : 'max-w-6xl lg:grid-cols-3'}">
-      {#if hasSections}
-        <!-- 좌측 절 목차 — xl+ sticky rail (그 아래 viewport 는 본문 상단 collapsible) -->
-        <aside class="hidden xl:block xl:sticky xl:top-6 xl:self-start xl:max-h-[calc(100vh-3rem)] xl:overflow-y-auto">
-          <Card>
-            <SectionOutline {sections} onJump={jumpToSection} {activeKey} />
-          </Card>
-        </aside>
-      {/if}
-
-      <!-- 본문 (좌측 목차 없을 때 lg 2/3) -->
-      <div class="{hasSections ? '' : 'lg:col-span-2'} space-y-4">
-        {#if hasSections}
-          <!-- xl 미만: 절 목차 접이식 -->
-          <details class="xl:hidden">
-            <summary class="cursor-pointer text-sm text-dim px-1 py-2 select-none">절 목차 ({sections.length})</summary>
-            <Card class="mt-2"><SectionOutline {sections} onJump={jumpToSection} {activeKey} /></Card>
-          </details>
-        {/if}
-        <!-- Affordance row -->
-        <div class="flex flex-wrap items-center gap-2">
-          {#if doc.edit_url}
-            <Button
-              variant="secondary"
-              size="sm"
-              icon={ExternalLink}
-              href={doc.edit_url}
-              target="_blank"
-            >
-              Synology 편집
-            </Button>
-          {/if}
-          <Button variant="secondary" size="sm" icon={Download} onclick={downloadOriginal}>
-            원본 다운로드
-          </Button>
-          {#if doc.preview_status === 'ready'}
-            <Button variant="secondary" size="sm" icon={FileText} onclick={downloadPdf}>
-              PDF 다운로드
-            </Button>
-          {/if}
-          <Button variant="secondary" size="sm" icon={Link2} onclick={copyLink}>
-            링크 복사
-          </Button>
+    <!-- ════ 상단 띠: 문서 헤더 ════ -->
+    <div class="bg-surface border border-default rounded-card px-4 py-3 mb-4">
+      <div class="flex items-start justify-between gap-3 flex-wrap">
+        <div class="flex-1 min-w-0">
+          <div class="flex items-center gap-2 flex-wrap mb-1.5">
+            {#if doc.ai_domain}
+              <span class="inline-flex items-center gap-1 text-[11px] font-semibold" style="color:#b5840a">
+                <span class="w-2 h-2 rounded-full" style="background:#b5840a"></span>{domainLabel(doc.ai_domain)}
+              </span>
+            {/if}
+            {#if doc.ai_sub_group}<span class="text-[11px] text-faint">{doc.ai_sub_group}</span>{/if}
+            <span class="text-[10px] font-bold rounded px-1.5 py-px uppercase" style="background:#f7e7e3;color:#c0564a">{doc.file_format}{#if canShowMarkdown}→MD{/if}</span>
+            {#if doc.ai_analysis_tier === 'deep'}<span class="text-[10px] font-bold rounded px-1.5 py-px" style="background:#e3ebdf;color:#3d7256">tier DEEP</span>{/if}
+            {#if doc.ai_confidence != null}<span class="text-[11px] text-dim">신뢰도 <b class="text-success">{doc.ai_confidence.toFixed(2)}</b></span>{/if}
+          </div>
+          <h1 class="text-lg font-bold text-text leading-snug">{doc.title}</h1>
+        </div>
+        <div class="flex items-center gap-1.5 shrink-0">
+          {#if doc.edit_url}<Button variant="secondary" size="sm" icon={ExternalLink} href={doc.edit_url} target="_blank">Synology</Button>{/if}
+          <Button variant="secondary" size="sm" icon={Download} onclick={downloadOriginal}>원본</Button>
+          <Button variant="secondary" size="sm" icon={Link2} onclick={copyLink}>링크</Button>
           {#if doc.category === 'library'}
-            <Button
-              variant={noteOpen ? 'primary' : 'secondary'}
-              size="sm"
-              icon={noteOpen ? X : PenLine}
-              onclick={toggleNote}
-            >
-              {noteOpen ? '필기 닫기' : '필기'}
-            </Button>
+            <Button variant={noteOpen ? 'primary' : 'secondary'} size="sm" icon={noteOpen ? X : PenLine} onclick={toggleNote}>{noteOpen ? '필기 닫기' : '필기'}</Button>
+          {/if}
+        </div>
+      </div>
+    </div>
+
+    {#if useSectionView}
+      <!-- ════ 3영역: 트리 | 절 집중 | 레일 ════ -->
+      <!-- 모바일: 본문(절 집중) 메인 + 절 구조/인사이트 접이 -->
+      <details class="xl:hidden bg-surface border border-default rounded-card mb-3 group">
+        <summary class="cursor-pointer list-none flex items-center justify-between px-4 py-2.5 text-xs font-semibold text-dim select-none">절 구조 ({sections.length}절)<ChevronRight size={14} class="transition-transform group-open:rotate-90 text-faint" /></summary>
+        <div class="px-4 pb-3">{@render treeNav()}</div>
+      </details>
+
+      <div class="grid grid-cols-1 xl:grid-cols-[252px_minmax(0,1fr)_336px] gap-4 items-start">
+        <!-- 좌 트리 (xl+ sticky) -->
+        <aside class="hidden xl:block xl:sticky xl:top-4 xl:self-start xl:max-h-[calc(100vh-2rem)] xl:overflow-y-auto bg-surface border border-default rounded-card p-3.5">
+          {@render treeNav()}
+        </aside>
+
+        <!-- 중 절 집중 뷰 -->
+        <div class="min-w-0 bg-surface border border-default rounded-card p-5">
+          {#if selectedSection}
+            {@const tm = typeMeta(selectedSection.section_type)}
+            <!-- breadcrumb -->
+            <div class="flex items-center gap-1.5 text-[11px] text-faint mb-2 flex-wrap">
+              <span class="truncate max-w-[180px]">{doc.title}</span>
+              {#each pathSegments(selectedSection.heading_path) as seg}<span>/</span><span class="text-dim">{seg}</span>{/each}
+            </div>
+            <!-- 제목 + 유형 배지 -->
+            <div class="flex items-start justify-between gap-3 mb-3">
+              <h2 class="text-xl font-bold text-text leading-snug min-w-0">{secTitle(selectedSection)}</h2>
+              {#if tm.label}<span class="shrink-0 text-[11px] font-semibold rounded-full px-2.5 py-1" style="background:{tm.color}1a;color:{tm.color}">{tm.label}</span>{/if}
+            </div>
+            <!-- 신뢰도 막대 -->
+            {#if selectedSection.confidence != null}
+              <div class="flex items-center gap-2.5 mb-3">
+                <span class="text-[11px] text-dim">신뢰도</span>
+                <span class="flex-1 max-w-[260px] h-1.5 rounded-full bg-default overflow-hidden">
+                  <span class="block h-full rounded-full" style="width:{Math.round(selectedSection.confidence * 100)}%;background:{confColor(selectedSection.confidence)}"></span>
+                </span>
+                <span class="text-xs font-bold tabular-nums" style="color:{confColor(selectedSection.confidence)}">{selectedSection.confidence.toFixed(2)}</span>
+              </div>
+            {/if}
+            <!-- 저신뢰 경고 -->
+            {#if isLowConf(selectedSection.confidence)}
+              <div class="flex items-start gap-2 bg-surface-hover border border-warning/50 rounded-lg px-3 py-2 mb-3 text-xs text-warning">
+                <span class="shrink-0 w-4 h-4 rounded-full border border-warning text-warning text-[10px] font-extrabold flex items-center justify-center mt-px">!</span>
+                <span>저신뢰 절 — 표·수식 추출이 불완전할 수 있습니다. 정확한 내용은 원본을 확인하세요.</span>
+              </div>
+            {/if}
+            <!-- 절 요약 (인용) -->
+            {#if selectedSection.summary}
+              <div class="border-l-[3px] border-accent bg-surface-hover rounded-r-lg px-4 py-3 mb-4">
+                <div class="text-[10px] font-bold text-dim uppercase tracking-wide mb-1">절 요약</div>
+                <p class="text-text leading-relaxed whitespace-pre-line">{selectedSection.summary}</p>
+              </div>
+            {/if}
+            <!-- 절 본문 -->
+            {#if selectedBodyHtml}
+              <div class="prose prose-base max-w-none text-text">{@html selectedBodyHtml}</div>
+            {:else}
+              <p class="text-faint text-sm italic">이 절의 본문은 추출되지 않았습니다. 헤더의 '원본'에서 확인하세요.</p>
+            {/if}
+            <!-- 풋터: 이전/다음 절 -->
+            <div class="flex items-center justify-between mt-5 pt-3 border-t border-default text-xs">
+              <button type="button" disabled={selIdx <= 0} onclick={() => selIdx > 0 && selectSection(sections[selIdx - 1].chunk_id)}
+                class="flex items-center gap-1 text-dim hover:text-accent disabled:opacity-30 disabled:cursor-not-allowed"><ChevronLeft size={14} />이전 절</button>
+              <span class="text-faint tabular-nums">{selIdx + 1} / {sections.length}</span>
+              <button type="button" disabled={selIdx >= sections.length - 1} onclick={() => selIdx < sections.length - 1 && selectSection(sections[selIdx + 1].chunk_id)}
+                class="flex items-center gap-1 text-dim hover:text-accent disabled:opacity-30 disabled:cursor-not-allowed">다음 절<ChevronRight size={14} /></button>
+            </div>
           {/if}
         </div>
 
-        <!-- 뷰어 — 모바일 가독성: 본문 폰트 키우고 line-height 늘림 -->
-        <Card class="min-h-[500px]">
+        <!-- 우 슬림 레일 -->
+        <aside class="min-w-0">
+          <!-- 모바일: 인사이트 접이 / xl: 상시 -->
+          <details open class="xl:hidden bg-surface border border-default rounded-card mb-2 group">
+            <summary class="cursor-pointer list-none flex items-center justify-between px-4 py-2.5 text-xs font-semibold text-dim select-none">인사이트<ChevronRight size={14} class="transition-transform group-open:rotate-90 text-faint" /></summary>
+            <div class="px-3 pb-3">{@render rail()}</div>
+          </details>
+          <div class="hidden xl:block">{@render rail()}</div>
+        </aside>
+      </div>
+    {:else}
+      <!-- ════ Fallback: 절 없음 — 본문/뷰어 + 레일 (D3 빈 절 graceful) ════ -->
+      <div class="grid grid-cols-1 xl:grid-cols-[minmax(0,1fr)_336px] gap-4 items-start">
+        <div class="min-w-0 bg-surface border border-default rounded-card p-5 min-h-[400px]">
+          {#if !hasSections && canShowMarkdown}
+            <p class="text-[11px] text-faint mb-3">이 문서는 절 분석이 없습니다 (짧은 문서이거나 분석 전) — 전체 본문으로 표시합니다.</p>
+          {/if}
           {#if viewerType === 'markdown' || viewerType === 'hwp-markdown'}
-            <MarkdownDoc
-              documentId={doc.id}
-              mdContent={doc.md_content}
-              mdFrontmatter={doc.md_frontmatter}
-              mdStatus={doc.md_status}
-              mdExtractionError={doc.md_extraction_error}
-              mdExtractionQuality={doc.md_extraction_quality}
-              anchorMap={anchorMap}
-              extractedText={doc.extracted_text || rawMarkdown}
-              class="prose prose-invert prose-base lg:prose-sm max-w-none"
-            />
+            <MarkdownDoc documentId={doc.id} mdContent={doc.md_content} mdFrontmatter={doc.md_frontmatter} mdStatus={doc.md_status} mdExtractionError={doc.md_extraction_error} mdExtractionQuality={doc.md_extraction_quality} extractedText={doc.extracted_text || rawMarkdown} class="prose prose-base max-w-none" />
           {:else if viewerType === 'pdf'}
             <div class="mb-2 flex items-center gap-2">
-              <MarkdownStatusBadge
-                mdStatus={doc.md_status}
-                mdExtractionError={doc.md_extraction_error}
-                mdExtractionQuality={doc.md_extraction_quality}
-              />
+              <MarkdownStatusBadge mdStatus={doc.md_status} mdExtractionError={doc.md_extraction_error} mdExtractionQuality={doc.md_extraction_quality} />
               {#if canShowMarkdown}
-                <Button
-                  size="sm"
-                  variant={pdfViewMode === 'markdown' ? 'primary' : 'secondary'}
-                  onclick={() => (pdfViewMode = 'markdown')}
-                >
-                  Markdown
-                </Button>
-                <Button
-                  size="sm"
-                  variant={pdfViewMode === 'pdf' ? 'primary' : 'secondary'}
-                  onclick={() => (pdfViewMode = 'pdf')}
-                >
-                  PDF 원본
-                </Button>
+                <Button size="sm" variant={pdfViewMode === 'markdown' ? 'primary' : 'secondary'} onclick={() => (pdfViewMode = 'markdown')}>Markdown</Button>
+                <Button size="sm" variant={pdfViewMode === 'pdf' ? 'primary' : 'secondary'} onclick={() => (pdfViewMode = 'pdf')}>PDF 원본</Button>
               {/if}
             </div>
             {#if pdfViewMode === 'markdown' && canShowMarkdown}
-              <MarkdownDoc
-                documentId={doc.id}
-                mdContent={doc.md_content}
-                mdFrontmatter={doc.md_frontmatter}
-                mdStatus={doc.md_status}
-                mdExtractionError={doc.md_extraction_error}
-                mdExtractionQuality={doc.md_extraction_quality}
-                extractedText={doc.extracted_text}
-                class="prose prose-invert prose-base lg:prose-sm max-w-none"
-              />
+              <MarkdownDoc documentId={doc.id} mdContent={doc.md_content} mdFrontmatter={doc.md_frontmatter} mdStatus={doc.md_status} mdExtractionError={doc.md_extraction_error} mdExtractionQuality={doc.md_extraction_quality} extractedText={doc.extracted_text} class="prose prose-base max-w-none" />
             {:else}
-              <iframe
-                src="/api/documents/{doc.id}/file?token={getAccessToken()}"
-                class="w-full h-[80vh] rounded"
-                title={doc.title}
-              ></iframe>
+              <iframe src="/api/documents/{doc.id}/file?token={getAccessToken()}" class="w-full h-[80vh] rounded" title={doc.title}></iframe>
             {/if}
           {:else if viewerType === 'image'}
-            <img
-              src="/api/documents/{doc.id}/file?token={getAccessToken()}"
-              alt={doc.title}
-              class="max-w-full rounded"
-            />
+            <img src="/api/documents/{doc.id}/file?token={getAccessToken()}" alt={doc.title} class="max-w-full rounded" />
           {:else if viewerType === 'synology'}
-            <EmptyState
-              icon={ExternalLink}
-              title="Synology Office 문서"
-              description="외부 편집기에서 열어야 합니다."
-            >
-              <Button
-                variant="primary"
-                size="sm"
-                href={doc.edit_url || 'https://link.hyungi.net'}
-                target="_blank"
-              >
-                새 창에서 열기
-              </Button>
+            <EmptyState icon={ExternalLink} title="Synology Office 문서" description="외부 편집기에서 열어야 합니다.">
+              <Button variant="primary" size="sm" href={doc.edit_url || 'https://link.hyungi.net'} target="_blank">새 창에서 열기</Button>
             </EmptyState>
           {:else if viewerType === 'article'}
-            <div>
-              <h1 class="text-xl font-bold text-text mb-3">{doc.title}</h1>
-              <div class="flex items-center gap-2 mb-4 text-xs text-dim">
-                <span>출처: {doc.source_channel}</span>
-                <span class="text-faint">·</span>
-                <span>
-                  {new Date(doc.created_at).toLocaleDateString('ko-KR', {
-                    year: 'numeric',
-                    month: 'short',
-                    day: 'numeric',
-                  })}
-                </span>
-              </div>
-              {#if doc.md_content || doc.extracted_text}
-                <!-- article = 텍스트 네이티브(markdown 변환 비대상). md_status='skipped' 라도
-                     "Markdown 제외" badge 를 띄우지 않도록 mdStatus 미전달(badge 는 mdStatus 로만 구동). -->
-                <MarkdownDoc
-                  documentId={doc.id}
-                  mdContent={doc.md_content}
-                  mdFrontmatter={doc.md_frontmatter}
-                  mdStatus={null}
-                  mdExtractionError={doc.md_extraction_error}
-                  mdExtractionQuality={doc.md_extraction_quality}
-                  extractedText={doc.extracted_text}
-                  class="mb-6"
-                />
-              {/if}
-              {#if doc.edit_url}
-                <Button
-                  variant="primary"
-                  size="sm"
-                  icon={ExternalLink}
-                  href={doc.edit_url}
-                  target="_blank"
-                >
-                  원문 보기
-                </Button>
-              {/if}
-            </div>
+            {#if doc.md_content || doc.extracted_text}
+              <MarkdownDoc documentId={doc.id} mdContent={doc.md_content} mdFrontmatter={doc.md_frontmatter} mdStatus={null} mdExtractionError={doc.md_extraction_error} mdExtractionQuality={doc.md_extraction_quality} extractedText={doc.extracted_text} class="prose prose-base max-w-none" />
+            {/if}
+            {#if doc.edit_url}<div class="mt-4"><Button variant="primary" size="sm" icon={ExternalLink} href={doc.edit_url} target="_blank">원문 보기</Button></div>{/if}
           {:else}
-            <EmptyState
-              icon={FileText}
-              title="인앱 미리보기 미지원"
-              description="포맷: {doc.file_format}"
-            />
+            <EmptyState icon={FileText} title="인앱 미리보기 미지원" description="포맷: {doc.file_format}" />
           {/if}
-        </Card>
-
-        <!-- 손글씨 노트 패드 (자료실 자료, "필기" 토글 시) -->
-        {#if noteOpen && doc.category === 'library' && noteLoaded}
-          <Card class="overflow-hidden p-0">
-            <div class="h-[60vh] min-h-[400px] flex flex-col">
-              <HandwriteCanvas
-                sessionId={doc.id}
-                initialStrokes={noteStrokes}
-                onChange={(strokes) => saveNote(strokes)}
-              />
-            </div>
-          </Card>
-        {/if}
+        </div>
+        <aside class="min-w-0">
+          <details open class="xl:hidden bg-surface border border-default rounded-card mb-2 group">
+            <summary class="cursor-pointer list-none flex items-center justify-between px-4 py-2.5 text-xs font-semibold text-dim select-none">인사이트<ChevronRight size={14} class="transition-transform group-open:rotate-90 text-faint" /></summary>
+            <div class="px-3 pb-3">{@render rail()}</div>
+          </details>
+          <div class="hidden xl:block">{@render rail()}</div>
+        </aside>
       </div>
+    {/if}
 
-      <!-- 오른쪽 — 슬림 전역 인사이트 레일 (D3: 탭 게이트 제거, 요약·심층·불일치 상시 노출).
-           정보/관리는 접이(<details>) — 데스크탑은 인사이트 상시, 모바일은 본문 메인 + 열어서 확인. -->
-      <aside class="min-w-0 space-y-3">
-        {#if doc.category === 'library'}
-          <Card>
-            <ReadCounter
-              documentId={doc.id}
-              initialCount={doc.read_count ?? 0}
-              initialLastReadAt={doc.last_read_at ?? null}
-            />
-          </Card>
-        {/if}
+    <!-- 손글씨 노트 -->
+    {#if noteOpen && doc.category === 'library' && noteLoaded}
+      <div class="bg-surface border border-default rounded-card overflow-hidden mt-4">
+        <div class="h-[60vh] min-h-[400px] flex flex-col">
+          <HandwriteCanvas sessionId={doc.id} initialStrokes={noteStrokes} onChange={(strokes) => saveNote(strokes)} />
+        </div>
+      </div>
+    {/if}
 
-        <!-- 요약·분석 — 기본 펼침(데스크탑 상시감, 모바일 접기 가능) -->
-        <details open class="bg-surface border border-default rounded-card overflow-hidden group">
-          <summary class="cursor-pointer list-none flex items-center justify-between px-3.5 py-2.5 text-xs font-semibold text-dim uppercase tracking-wide select-none">
-            <span>요약 · 분석</span>
-            <ChevronRight size={14} class="transition-transform group-open:rotate-90 text-faint" />
-          </summary>
-          <div class="px-3.5 pb-3.5 space-y-4">
-            <AnalysisPanel docId={doc.id} doc={doc} />
-            <AIClassificationEditor {doc} />
-            <div>
-              <h4 class="text-xs font-semibold text-dim uppercase mb-1.5">관련 문서</h4>
-              <!-- TODO(backend): GET /documents/{id}/related?limit=10 (벡터 유사도) — v1 제외(자리만) -->
-              <EmptyState
-                icon={FileText}
-                title="추후 지원"
-                description="관련 문서 추천은 backend 연동 후 제공됩니다."
-              />
-            </div>
-          </div>
-        </details>
-
-        <!-- 문서 정보 — 접이(기본 닫힘) -->
-        <details class="bg-surface border border-default rounded-card overflow-hidden group">
-          <summary class="cursor-pointer list-none flex items-center justify-between px-3.5 py-2.5 text-xs font-semibold text-dim uppercase tracking-wide select-none">
-            <span>문서 정보</span>
-            <ChevronRight size={14} class="transition-transform group-open:rotate-90 text-faint" />
-          </summary>
-          <div class="px-3.5 pb-3.5 space-y-3">
-            <FileInfoView {doc} />
-            <ProcessingStatusView {doc} />
-          </div>
-        </details>
-
-        <!-- 관리 — 접이(기본 닫힘) -->
-        <details class="bg-surface border border-default rounded-card overflow-hidden group">
-          <summary class="cursor-pointer list-none flex items-center justify-between px-3.5 py-2.5 text-xs font-semibold text-dim uppercase tracking-wide select-none">
-            <span>관리</span>
-            <ChevronRight size={14} class="transition-transform group-open:rotate-90 text-faint" />
-          </summary>
-          <div class="px-3.5 pb-3.5 space-y-3">
-            <LibraryPathEditor {doc} />
-            <NoteEditor {doc} />
-            <EditUrlEditor {doc} />
-            <TagsEditor {doc} />
-            <div class="pt-2 border-t border-default">
-              <DocumentDangerZone {doc} ondelete={handleDocDelete} />
-            </div>
-          </div>
-        </details>
-      </aside>
-    </div>
-
-    <!-- 모바일 sticky 하단 바 — 자료실 자료의 학습 흐름 네비게이션 -->
+    <!-- 모바일 학습 흐름 네비 (자료실) -->
     {#if doc.category === 'library'}
       <div class="lg:hidden fixed bottom-0 inset-x-0 z-30 bg-surface border-t border-default px-3 py-2 flex items-center gap-2 shadow-lg">
-        <button
-          type="button"
-          onclick={() => neighbors.prev && goto(`/documents/${neighbors.prev.id}`)}
-          disabled={!neighbors.prev}
-          class="px-2 py-2 rounded text-dim disabled:opacity-30 disabled:cursor-not-allowed"
-          aria-label="이전 자료"
-        ><ChevronLeft size={20} /></button>
-
-        <button
-          type="button"
-          onclick={readAndGoNext}
-          disabled={!neighbors.next}
-          class="flex-1 flex items-center justify-center gap-1.5 px-3 py-2.5 rounded-lg bg-accent text-white text-sm font-medium disabled:opacity-50"
-        >
-          <Check size={16} />
-          {#if neighbors.next}
-            1회독 완료 + 다음
-          {:else}
-            1회독 완료 (마지막 자료)
-          {/if}
+        <button type="button" onclick={() => neighbors.prev && goto(`/documents/${neighbors.prev.id}`)} disabled={!neighbors.prev}
+          class="px-2 py-2 rounded text-dim disabled:opacity-30" aria-label="이전 자료"><ChevronLeft size={20} /></button>
+        <button type="button" onclick={readAndGoNext} disabled={!neighbors.next}
+          class="flex-1 flex items-center justify-center gap-1.5 px-3 py-2.5 rounded-lg bg-accent text-white text-sm font-medium disabled:opacity-50">
+          <Check size={16} />{#if neighbors.next}1회독 완료 + 다음{:else}1회독 완료 (마지막){/if}
         </button>
-
-        <button
-          type="button"
-          onclick={() => neighbors.next && goto(`/documents/${neighbors.next.id}`)}
-          disabled={!neighbors.next}
-          class="px-2 py-2 rounded text-dim disabled:opacity-30 disabled:cursor-not-allowed"
-          aria-label="다음 자료 (회독 카운트 안 함)"
-        ><ChevronRight size={20} /></button>
+        <button type="button" onclick={() => neighbors.next && goto(`/documents/${neighbors.next.id}`)} disabled={!neighbors.next}
+          class="px-2 py-2 rounded text-dim disabled:opacity-30" aria-label="다음 자료"><ChevronRight size={20} /></button>
       </div>
-      <!-- 본문이 sticky 바 뒤에 가리지 않도록 패딩 -->
       <div class="lg:hidden h-20"></div>
     {/if}
   {/if}