diff --git a/app/api/documents.py b/app/api/documents.py
index 13ff4a9..315d643 100644
--- a/app/api/documents.py
+++ b/app/api/documents.py
@@ -4,6 +4,7 @@ import shutil
 from datetime import datetime, timezone
 from pathlib import Path
 from typing import Annotated
+from urllib.parse import quote
 
 from fastapi import APIRouter, Depends, HTTPException, Query, UploadFile, status
 from fastapi.responses import FileResponse
@@ -74,6 +75,7 @@ class DocumentUpdate(BaseModel):
     ai_domain: str | None = None
     ai_sub_group: str | None = None
     ai_tags: list | None = None
+    user_tags: list | None = None
     user_note: str | None = None
     is_read: bool | None = None
     edit_url: str | None = None
@@ -141,6 +143,132 @@ async def get_document_tree(
     return build_tree(root)
 
 
+@router.get("/library-tree")
+async def get_library_tree(
+    user: Annotated[User, Depends(get_current_user)],
+    session: Annotated[AsyncSession, Depends(get_session)],
+):
+    """자료실 트리 (user_tags @library/ 경로 기반, unique doc count)"""
+    from core.library import LIBRARY_PREFIX
+
+    result = await session.execute(
+        select(Document.id, Document.user_tags).where(
+            Document.deleted_at == None,  # noqa: E711
+            Document.user_tags != None,  # noqa: E711
+        )
+    )
+
+    root: dict = {}
+    for doc_id, tags in result:
+        if not tags:
+            continue
+        seen_ancestors: set[str] = set()
+        for tag in tags:
+            if not isinstance(tag, str) or not tag.startswith(LIBRARY_PREFIX):
+                continue
+            path = tag[len(LIBRARY_PREFIX):]
+            parts = path.split("/")
+            node = root
+            for i, part in enumerate(parts):
+                if part not in node:
+                    node[part] = {"_docs": set(), "_children": {}}
+                ancestor_key = "/".join(parts[: i + 1])
+                if ancestor_key not in seen_ancestors:
+                    node[part]["_docs"].add(doc_id)
+                    seen_ancestors.add(ancestor_key)
+                node = node[part]["_children"]
+
+    def build_library_tree(d: dict, prefix: str = "") -> list[dict]:
+        nodes = []
+        for name, data in sorted(d.items()):
+            if name.startswith("_"):
+                continue
+            path = f"{prefix}/{name}" if prefix else name
+            children = build_library_tree(data["_children"], path)
+            nodes.append({
+                "name": name,
+                "path": path,
+                "count": len(data["_docs"]),
+                "children": children,
+            })
+        return nodes
+
+    return build_library_tree(root)
+
+
+@router.get("/library", response_model=DocumentListResponse)
+async def list_library_documents(
+    user: Annotated[User, Depends(get_current_user)],
+    session: Annotated[AsyncSession, Depends(get_session)],
+    path: str | None = None,
+    q: str | None = None,
+    sort: str = Query("updated_desc"),
+    page: int = Query(1, ge=1),
+    page_size: int = Query(20, ge=1, le=100),
+):
+    """자료실 문서 목록 (prefix match, title 검색, 정렬)"""
+    from sqlalchemy import text as sql_text
+
+    from core.library import LIBRARY_PREFIX, normalize_library_path
+
+    # path 쿼리 정규화 (PATCH와 동일 semantics)
+    if path:
+        try:
+            path = normalize_library_path(path)
+        except ValueError as e:
+            raise HTTPException(status_code=400, detail=str(e))
+
+    query = select(Document).where(
+        Document.deleted_at == None,  # noqa: E711
+    )
+
+    if path:
+        exact = f"{LIBRARY_PREFIX}{path}"
+        prefix = f"{LIBRARY_PREFIX}{path}/%"
+        query = query.where(
+            sql_text("""
+                EXISTS (
+                    SELECT 1 FROM jsonb_array_elements_text(documents.user_tags) AS t
+                    WHERE t = :exact OR t LIKE :prefix
+                )
+            """).bindparams(exact=exact, prefix=prefix)
+        )
+    else:
+        query = query.where(
+            sql_text("""
+                EXISTS (
+                    SELECT 1 FROM jsonb_array_elements_text(documents.user_tags) AS t
+                    WHERE t LIKE '@library/%'
+                )
+            """)
+        )
+
+    if q:
+        query = query.where(Document.title.ilike(f"%{q}%"))
+
+    # 전체 건수
+    count_query = select(func.count()).select_from(query.subquery())
+    total = (await session.execute(count_query)).scalar()
+
+    # 정렬
+    sort_map = {
+        "updated_desc": Document.updated_at.desc(),
+        "title_asc": Document.title.asc(),
+        "created_desc": Document.created_at.desc(),
+    }
+    query = query.order_by(sort_map.get(sort, Document.updated_at.desc()))
+    query = query.offset((page - 1) * page_size).limit(page_size)
+    result = await session.execute(query)
+    items = result.scalars().all()
+
+    return DocumentListResponse(
+        items=[DocumentResponse.model_validate(doc) for doc in items],
+        total=total,
+        page=page,
+        page_size=page_size,
+    )
+
+
 @router.get("/", response_model=DocumentListResponse)
 async def list_documents(
     user: Annotated[User, Depends(get_current_user)],
@@ -206,6 +334,7 @@ async def get_document_file(
     doc_id: int,
     session: Annotated[AsyncSession, Depends(get_session)],
     token: str | None = Query(None, description="Bearer token (iframe용)"),
+    download: bool = Query(False, description="true면 attachment (브라우저 다운로드)"),
     user: User | None = Depends(lambda: None),
 ):
     """문서 원본 파일 서빙 (Bearer 헤더 또는 ?token= 쿼리 파라미터)"""
@@ -246,10 +375,19 @@ async def get_document_file(
     suffix = file_path.suffix.lower()
     media_type = media_types.get(suffix, "application/octet-stream")
 
+    # Content-Disposition: download=true면 attachment (한글 filename* 호환)
+    if download:
+        raw_title = doc.title or f"document-{doc_id}"
+        ascii_fallback = raw_title.encode("ascii", "replace").decode()
+        utf8_encoded = quote(f"{raw_title}{suffix}")
+        disposition = f'attachment; filename="{ascii_fallback}{suffix}"; filename*=UTF-8\'\'{utf8_encoded}'
+    else:
+        disposition = "inline"
+
     return FileResponse(
         path=str(file_path),
         media_type=media_type,
-        headers={"Content-Disposition": "inline"},
+        headers={"Content-Disposition": disposition},
     )
 
 
@@ -324,11 +462,21 @@ async def update_document(
     session: Annotated[AsyncSession, Depends(get_session)],
 ):
     """문서 메타데이터 수정 (수동 오버라이드)"""
+    from core.library import validate_user_tags
+
     doc = await session.get(Document, doc_id)
     if not doc:
         raise HTTPException(status_code=404, detail="문서를 찾을 수 없습니다")
 
     update_data = body.model_dump(exclude_unset=True)
+
+    # user_tags 검증: @library/ 경로 정규화 + 타입/중복 체크
+    if "user_tags" in update_data and update_data["user_tags"] is not None:
+        try:
+            update_data["user_tags"] = validate_user_tags(update_data["user_tags"])
+        except (TypeError, ValueError) as e:
+            raise HTTPException(status_code=400, detail=str(e))
+
     for field, value in update_data.items():
         setattr(doc, field, value)
     doc.updated_at = datetime.now(timezone.utc)
@@ -375,6 +523,7 @@ async def get_document_preview(
     doc_id: int,
     session: Annotated[AsyncSession, Depends(get_session)],
     token: str | None = Query(None, description="Bearer token (iframe용)"),
+    download: bool = Query(False, description="true면 attachment (PDF 다운로드)"),
 ):
     """PDF 미리보기 캐시 서빙"""
     from core.auth import decode_token
@@ -394,10 +543,18 @@ async def get_document_preview(
     if not preview_path.exists():
         raise HTTPException(status_code=404, detail="미리보기가 아직 생성되지 않았습니다")
 
+    if download:
+        raw_title = doc.title or f"document-{doc_id}"
+        ascii_fallback = raw_title.encode("ascii", "replace").decode()
+        utf8_encoded = quote(f"{raw_title}.pdf")
+        disposition = f'attachment; filename="{ascii_fallback}.pdf"; filename*=UTF-8\'\'{utf8_encoded}'
+    else:
+        disposition = "inline"
+
     return FileResponse(
         path=str(preview_path),
         media_type="application/pdf",
-        headers={"Content-Disposition": "inline"},
+        headers={"Content-Disposition": disposition},
     )
 
 
diff --git a/app/core/library.py b/app/core/library.py
new file mode 100644
index 0000000..5d32dda
--- /dev/null
+++ b/app/core/library.py
@@ -0,0 +1,79 @@
+"""자료실 경로 유틸.
+
+user_tags 내 @library/ 접두사 태그를 정규화·검증·추출한다.
+"""
+
+LIBRARY_PREFIX = "@library/"
+MAX_DEPTH = 5
+MAX_SEGMENT_LEN = 30
+
+
+def normalize_library_path(raw: str) -> str:
+    """경로 정규화. 엄격 정책 — 규칙 위반 시 ValueError 즉시 raise.
+
+    규칙:
+    - 앞뒤 공백·슬래시 제거
+    - segment별 trim
+    - 빈 segment(// 또는 공백만) → ValueError
+    - segment 30자 초과 → ValueError
+    - 5단계 초과 → ValueError
+
+    GET /documents/library?path= 쿼리에도 동일하게 적용.
+    """
+    stripped = raw.strip().strip("/")
+    if not stripped:
+        raise ValueError("빈 경로")
+
+    segments = stripped.split("/")
+    normalized: list[str] = []
+    for s in segments:
+        s = s.strip()
+        if not s:
+            raise ValueError("빈 세그먼트 (// 또는 공백만 있는 구간)")
+        if len(s) > MAX_SEGMENT_LEN:
+            raise ValueError(f"세그먼트 '{s}'가 {MAX_SEGMENT_LEN}자 초과")
+        normalized.append(s)
+
+    if len(normalized) > MAX_DEPTH:
+        raise ValueError(f"최대 {MAX_DEPTH}단계까지 가능")
+
+    return "/".join(normalized)
+
+
+def extract_library_paths(user_tags: list[str] | None) -> list[str]:
+    """user_tags에서 @library/ 경로만 추출 (prefix 포함)."""
+    if not user_tags:
+        return []
+    return [t for t in user_tags if t.startswith(LIBRARY_PREFIX)]
+
+
+def validate_user_tags(tags: list) -> list[str]:
+    """user_tags 전체 검증. 입력 순서 보존, 중복 제거.
+
+    - 문자열이 아닌 원소 → TypeError
+    - 빈 문자열 / 공백만 있는 태그 → 제거
+    - 일반 태그 → strip() 후 통과
+    - @library/ 태그 → normalize_library_path() 적용
+    - 중복 → 첫 출현만 유지 (입력 순서 보존)
+    """
+    result: list[str] = []
+    for tag in tags:
+        if not isinstance(tag, str):
+            raise TypeError(f"태그는 문자열이어야 합니다: {tag!r}")
+        tag = tag.strip()
+        if not tag:
+            continue
+        if tag.startswith(LIBRARY_PREFIX):
+            path = tag[len(LIBRARY_PREFIX):]
+            normalized = normalize_library_path(path)
+            tag = f"{LIBRARY_PREFIX}{normalized}"
+        result.append(tag)
+
+    # 중복 제거 (입력 순서 보존)
+    seen: set[str] = set()
+    deduped: list[str] = []
+    for t in result:
+        if t not in seen:
+            seen.add(t)
+            deduped.append(t)
+    return deduped
diff --git a/frontend/src/lib/components/Sidebar.svelte b/frontend/src/lib/components/Sidebar.svelte
index 15e4c29..0742713 100644
--- a/frontend/src/lib/components/Sidebar.svelte
+++ b/frontend/src/lib/components/Sidebar.svelte
@@ -2,7 +2,7 @@
   import { page } from '$app/stores';
   import { goto } from '$app/navigation';
   import { api } from '$lib/api';
-  import { ChevronRight, ChevronDown, FolderOpen, Inbox, Clock, Mail, Scale, StickyNote } from 'lucide-svelte';
+  import { ChevronRight, ChevronDown, FolderOpen, FolderTree, Inbox, Clock, Mail, Scale, StickyNote } from 'lucide-svelte';
 
   let tree = $state([]);
   let loading = $state(true);
@@ -188,6 +188,13 @@
     >
       <Mail size={14} /> 이메일
     </button>
+    <a
+      href="/library"
+      class="w-full flex items-center gap-2 px-3 py-1.5 rounded-md text-sm transition-colors
+        {$page.url.pathname === '/library' ? 'bg-accent/15 text-accent' : 'text-dim hover:bg-surface hover:text-text'}"
+    >
+      <FolderTree size={14} /> 자료실
+    </a>
   </div>
 
   <!-- 메모 & Inbox -->
diff --git a/frontend/src/lib/components/editors/LibraryPathEditor.svelte b/frontend/src/lib/components/editors/LibraryPathEditor.svelte
new file mode 100644
index 0000000..ffcf8fe
--- /dev/null
+++ b/frontend/src/lib/components/editors/LibraryPathEditor.svelte
@@ -0,0 +1,216 @@
+<script>
+  // 자료실 경로 편집기 — user_tags에서 @library/ 접두사 관리
+  import { onMount } from 'svelte';
+  import { X, Plus, FolderPlus } from 'lucide-svelte';
+  import { api } from '$lib/api';
+  import { addToast } from '$lib/stores/toast';
+
+  let { doc } = $props();
+
+  const PREFIX = '@library/';
+
+  let libraryPaths = $derived(
+    (doc.user_tags || [])
+      .filter((t) => t.startsWith(PREFIX))
+      .map((t) => t.slice(PREFIX.length))
+  );
+
+  let newPath = $state('');
+  let editing = $state(false);
+  let existingPaths = $state([]);
+  let showSuggestions = $state(false);
+
+  let suggestions = $derived(
+    newPath.length >= 1
+      ? existingPaths
+          .filter(
+            (p) => p.toLowerCase().includes(newPath.toLowerCase()) && !libraryPaths.includes(p)
+          )
+          .slice(0, 5)
+      : []
+  );
+
+  // 입력 정규화 미리보기
+  let normalizedPreview = $derived(() => {
+    try {
+      return normalizePath(newPath);
+    } catch {
+      return null;
+    }
+  });
+
+  $effect(() => {
+    if (doc) {
+      newPath = '';
+      editing = false;
+    }
+  });
+
+  onMount(async () => {
+    try {
+      const tree = await api('/documents/library-tree');
+      existingPaths = flattenPaths(tree);
+    } catch {
+      /* 자동완성 실패해도 입력은 가능 */
+    }
+  });
+
+  function flattenPaths(nodes, prefix = '') {
+    let paths = [];
+    for (const n of nodes) {
+      const p = prefix ? `${prefix}/${n.name}` : n.name;
+      paths.push(p);
+      if (n.children?.length) paths.push(...flattenPaths(n.children, p));
+    }
+    return paths;
+  }
+
+  function normalizePath(raw) {
+    const stripped = raw.trim().replace(/^\/+|\/+$/g, '');
+    if (!stripped) throw new Error('빈 경로');
+    const segments = stripped.split('/');
+    const normalized = [];
+    for (const s of segments) {
+      const trimmed = s.trim();
+      if (!trimmed) throw new Error('빈 세그먼트');
+      if (trimmed.length > 30) throw new Error('세그먼트 30자 초과');
+      normalized.push(trimmed);
+    }
+    if (normalized.length > 5) throw new Error('최대 5단계');
+    return normalized.join('/');
+  }
+
+  async function addPath(rawPath) {
+    let path;
+    try {
+      path = normalizePath(rawPath);
+    } catch (e) {
+      addToast('error', e.message);
+      return;
+    }
+    const tag = `${PREFIX}${path}`;
+    if ((doc.user_tags || []).includes(tag)) {
+      addToast('warning', '이미 등록된 경로');
+      return;
+    }
+    const updated = [...(doc.user_tags || []), tag];
+    try {
+      await api(`/documents/${doc.id}`, {
+        method: 'PATCH',
+        body: JSON.stringify({ user_tags: updated }),
+      });
+      doc.user_tags = updated;
+      newPath = '';
+      addToast('success', '자료실 경로 추가됨');
+    } catch {
+      addToast('error', '경로 추가 실패');
+    }
+  }
+
+  async function removePath(pathToRemove) {
+    const tag = `${PREFIX}${pathToRemove}`;
+    const updated = (doc.user_tags || []).filter((t) => t !== tag);
+    try {
+      await api(`/documents/${doc.id}`, {
+        method: 'PATCH',
+        body: JSON.stringify({ user_tags: updated }),
+      });
+      doc.user_tags = updated;
+      addToast('success', '경로 삭제됨');
+    } catch {
+      addToast('error', '경로 삭제 실패');
+    }
+  }
+
+  function selectSuggestion(path) {
+    addPath(path);
+    showSuggestions = false;
+  }
+</script>
+
+<div>
+  <h4 class="text-xs font-semibold text-dim uppercase mb-1.5 flex items-center gap-1">
+    <FolderPlus size={12} />
+    자료실 경로
+  </h4>
+
+  <!-- 현재 경로 목록 -->
+  {#if libraryPaths.length > 0}
+    <div class="flex flex-col gap-1 mb-2">
+      {#each libraryPaths as path}
+        <div
+          class="flex items-center justify-between gap-1 px-2 py-1 bg-bg border border-default rounded text-xs"
+        >
+          <span class="text-text truncate" title={path}>{path}</span>
+          <button
+            type="button"
+            onclick={() => removePath(path)}
+            class="text-dim hover:text-error shrink-0"
+            aria-label="{path} 삭제"
+            title="삭제"
+          >
+            <X size={10} />
+          </button>
+        </div>
+      {/each}
+    </div>
+  {/if}
+
+  <!-- 입력 영역 -->
+  {#if editing}
+    <div class="relative">
+      <form
+        onsubmit={(e) => {
+          e.preventDefault();
+          addPath(newPath);
+        }}
+        class="flex gap-1"
+      >
+        <input
+          bind:value={newPath}
+          onfocus={() => (showSuggestions = true)}
+          onblur={() => setTimeout(() => (showSuggestions = false), 200)}
+          aria-label="자료실 경로"
+          placeholder="회사A/양식/안전"
+          class="flex-1 px-2 py-1 bg-bg border border-default rounded text-xs text-text outline-none focus:border-accent"
+        />
+        <button
+          type="submit"
+          class="px-2 py-1 text-xs bg-accent text-white rounded hover:bg-accent-hover"
+        >
+          추가
+        </button>
+      </form>
+
+      <!-- 자동완성 드롭다운 -->
+      {#if showSuggestions && suggestions.length > 0}
+        <div
+          class="absolute top-full left-0 right-0 mt-1 bg-surface border border-default rounded shadow-lg z-dropdown"
+        >
+          {#each suggestions as suggestion}
+            <button
+              type="button"
+              onmousedown={() => selectSuggestion(suggestion)}
+              class="w-full text-left px-2 py-1.5 text-xs text-dim hover:bg-surface-hover hover:text-text"
+            >
+              {suggestion}
+            </button>
+          {/each}
+        </div>
+      {/if}
+
+      <!-- 정규화 미리보기 -->
+      {#if newPath.trim() && normalizedPreview() && normalizedPreview() !== newPath.trim()}
+        <p class="text-[10px] text-dim mt-0.5">→ {normalizedPreview()}</p>
+      {/if}
+    </div>
+  {:else}
+    <button
+      type="button"
+      onclick={() => (editing = true)}
+      class="flex items-center gap-1 text-xs text-dim hover:text-accent"
+    >
+      <Plus size={12} /> 경로 추가
+    </button>
+  {/if}
+</div>
diff --git a/frontend/src/routes/+layout.svelte b/frontend/src/routes/+layout.svelte
index 030f097..c9c2473 100644
--- a/frontend/src/routes/+layout.svelte
+++ b/frontend/src/routes/+layout.svelte
@@ -82,7 +82,9 @@
           {/if}
           <a href="/" class="text-sm font-semibold hover:text-accent">PKM</a>
           <span class="text-dim text-xs">/</span>
-          <a href="/documents" class="text-xs hover:text-accent">문서</a>
+          <a href="/documents" class="text-xs hover:text-accent {isActive('/documents') ? 'text-accent' : ''}">문서</a>
+          <span class="text-faint text-xs">·</span>
+          <a href="/library" class="text-xs hover:text-accent {isActive('/library') ? 'text-accent' : ''}">자료실</a>
           <SystemStatusDot />
         </div>
         <div class="flex items-center gap-1">
diff --git a/frontend/src/routes/documents/[id]/+page.svelte b/frontend/src/routes/documents/[id]/+page.svelte
index 43bcdda..34f8e85 100644
--- a/frontend/src/routes/documents/[id]/+page.svelte
+++ b/frontend/src/routes/documents/[id]/+page.svelte
@@ -20,6 +20,7 @@
   import AIClassificationEditor from '$lib/components/editors/AIClassificationEditor.svelte';
   import FileInfoView from '$lib/components/editors/FileInfoView.svelte';
   import ProcessingStatusView from '$lib/components/editors/ProcessingStatusView.svelte';
+  import LibraryPathEditor from '$lib/components/editors/LibraryPathEditor.svelte';
   import DocumentDangerZone from '$lib/components/editors/DocumentDangerZone.svelte';
 
   marked.use({ mangle: false, headerIds: false });
@@ -80,14 +81,12 @@
       .catch(() => addToast('error', '복사 실패'));
   }
 
-  function downloadFile() {
-    const url = `/api/documents/${docId}/file?token=${getAccessToken()}`;
-    const a = document.createElement('a');
-    a.href = url;
-    a.download = doc?.title || `document-${docId}`;
-    document.body.appendChild(a);
-    a.click();
-    document.body.removeChild(a);
+  function downloadOriginal() {
+    window.open(`/api/documents/${docId}/file?token=${getAccessToken()}&download=true`);
+  }
+
+  function downloadPdf() {
+    window.open(`/api/documents/${docId}/preview?token=${getAccessToken()}&download=true`);
   }
 
   function handleDocDelete() {
@@ -141,9 +140,14 @@
               Synology 편집
             </Button>
           {/if}
-          <Button variant="secondary" size="sm" icon={Download} onclick={downloadFile}>
-            다운로드
+          <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>
@@ -225,6 +229,9 @@
 
       <!-- 오른쪽 (1/3) — editors stack -->
       <aside class="space-y-4">
+        <Card>
+          <LibraryPathEditor {doc} />
+        </Card>
         <Card>
           <NoteEditor {doc} />
         </Card>
diff --git a/frontend/src/routes/library/+page.svelte b/frontend/src/routes/library/+page.svelte
new file mode 100644
index 0000000..0daba5e
--- /dev/null
+++ b/frontend/src/routes/library/+page.svelte
@@ -0,0 +1,414 @@
+<script>
+  // 자료실 — 태그 기반 트리 문서 관리
+  import { onMount } from 'svelte';
+  import { page } from '$app/stores';
+  import { goto } from '$app/navigation';
+  import { api, getAccessToken } from '$lib/api';
+  import { addToast } from '$lib/stores/toast';
+  import {
+    ChevronRight,
+    ChevronDown,
+    FolderOpen,
+    ExternalLink,
+    Download,
+    FileText,
+  } from 'lucide-svelte';
+  import DocumentCard from '$lib/components/DocumentCard.svelte';
+  import FormatIcon from '$lib/components/FormatIcon.svelte';
+  import Button from '$lib/components/ui/Button.svelte';
+  import EmptyState from '$lib/components/ui/EmptyState.svelte';
+  import Skeleton from '$lib/components/ui/Skeleton.svelte';
+
+  // ─── 상태 ───
+
+  let tree = $state([]);
+  let treeLoading = $state(true);
+  let expanded = $state({});
+
+  let docs = $state([]);
+  let docsLoading = $state(false);
+  let total = $state(0);
+
+  let activePath = $derived($page.url.searchParams.get('path'));
+  let activeSort = $derived($page.url.searchParams.get('sort') || 'updated_desc');
+  let activeQ = $derived($page.url.searchParams.get('q') || '');
+  let activePage = $derived(Number($page.url.searchParams.get('page')) || 1);
+
+  const SORT_OPTIONS = [
+    { value: 'updated_desc', label: '최근 수정순' },
+    { value: 'title_asc', label: '제목순' },
+    { value: 'created_desc', label: '등록순' },
+  ];
+
+  const ODF_FORMATS = ['ods', 'odt', 'odp', 'odoc', 'osheet'];
+
+  // ─── 데이터 로드 ───
+
+  async function loadTree() {
+    treeLoading = true;
+    try {
+      tree = await api('/documents/library-tree');
+    } catch {
+      addToast('error', '자료실 트리 로딩 실패');
+    } finally {
+      treeLoading = false;
+    }
+  }
+
+  async function loadDocs() {
+    docsLoading = true;
+    try {
+      const params = new URLSearchParams();
+      if (activePath) params.set('path', activePath);
+      if (activeSort) params.set('sort', activeSort);
+      if (activeQ) params.set('q', activeQ);
+      params.set('page', String(activePage));
+      params.set('page_size', '20');
+      const result = await api(`/documents/library?${params}`);
+      docs = result.items;
+      total = result.total;
+    } catch {
+      addToast('error', '자료실 문서 로딩 실패');
+    } finally {
+      docsLoading = false;
+    }
+  }
+
+  onMount(() => {
+    loadTree();
+  });
+
+  // URL 파라미터 변경 시 문서 목록 재로드
+  $effect(() => {
+    // eslint-disable-next-line no-unused-expressions
+    activePath, activeSort, activeQ, activePage;
+    loadDocs();
+  });
+
+  // 선택된 경로의 부모 자동 펼치기
+  $effect(() => {
+    if (activePath) {
+      const parts = activePath.split('/');
+      let path = '';
+      for (const part of parts) {
+        path = path ? `${path}/${part}` : part;
+        expanded[path] = true;
+      }
+    }
+  });
+
+  let totalCount = $derived(tree.reduce((sum, n) => sum + n.count, 0));
+
+  // ─── 네비게이션 ───
+
+  function navigate(path) {
+    const params = new URLSearchParams($page.url.searchParams);
+    params.delete('page');
+    if (path) {
+      params.set('path', path);
+    } else {
+      params.delete('path');
+    }
+    const qs = params.toString();
+    goto(`/library${qs ? '?' + qs : ''}`, { noScroll: true });
+  }
+
+  function setSort(sort) {
+    const params = new URLSearchParams($page.url.searchParams);
+    params.set('sort', sort);
+    params.delete('page');
+    goto(`/library?${params}`, { noScroll: true });
+  }
+
+  function setSearch(q) {
+    const params = new URLSearchParams($page.url.searchParams);
+    if (q) {
+      params.set('q', q);
+    } else {
+      params.delete('q');
+    }
+    params.delete('page');
+    goto(`/library?${params}`, { noScroll: true });
+  }
+
+  function toggleExpand(path) {
+    expanded[path] = !expanded[path];
+  }
+
+  // ─── 문서 액션 ───
+
+  function getEditUrl(doc) {
+    if (doc.edit_url) return doc.edit_url;
+    if (ODF_FORMATS.includes(doc.file_format)) return 'https://link.hyungi.net';
+    return null;
+  }
+
+  function downloadOriginal(doc) {
+    window.open(`/api/documents/${doc.id}/file?token=${getAccessToken()}&download=true`);
+  }
+
+  function downloadPdf(doc) {
+    window.open(`/api/documents/${doc.id}/preview?token=${getAccessToken()}&download=true`);
+  }
+
+  // ─── 검색 debounce ───
+
+  let searchInput = $state(activeQ);
+  let searchTimer;
+
+  function handleSearchInput(e) {
+    searchInput = e.target.value;
+    clearTimeout(searchTimer);
+    searchTimer = setTimeout(() => setSearch(searchInput), 300);
+  }
+
+  // 페이지네이션
+  let totalPages = $derived(Math.ceil(total / 20));
+</script>
+
+<div class="p-4 lg:p-6">
+  <!-- breadcrumb -->
+  <div class="flex items-center gap-2 text-sm mb-4 text-dim">
+    <a href="/documents" class="hover:text-text">문서</a>
+    <span class="text-faint">/</span>
+    <span class="text-text">자료실</span>
+    {#if activePath}
+      {#each activePath.split('/') as segment, i}
+        <span class="text-faint">/</span>
+        <button
+          type="button"
+          onclick={() => navigate(activePath.split('/').slice(0, i + 1).join('/'))}
+          class="hover:text-text"
+        >
+          {segment}
+        </button>
+      {/each}
+    {/if}
+  </div>
+
+  <div class="max-w-7xl mx-auto grid grid-cols-1 lg:grid-cols-12 gap-6">
+    <!-- 왼쪽: 트리 (5/12) -->
+    <aside class="lg:col-span-5 xl:col-span-4">
+      <div class="bg-surface border border-default rounded-card p-3">
+        <h2 class="text-xs font-semibold text-dim uppercase tracking-wider mb-2">분류</h2>
+
+        <!-- 전체 -->
+        <button
+          onclick={() => navigate(null)}
+          class="w-full flex items-center justify-between px-3 py-2 rounded-md text-sm transition-colors mb-1
+            {!activePath ? 'bg-accent/15 text-accent' : 'text-text hover:bg-surface-hover'}"
+        >
+          <span class="flex items-center gap-2">
+            <FolderOpen size={16} />
+            전체
+          </span>
+          {#if totalCount > 0}
+            <span class="text-xs text-dim">{totalCount}</span>
+          {/if}
+        </button>
+
+        <!-- 트리 -->
+        {#if treeLoading}
+          {#each Array(3) as _}
+            <div class="h-8 bg-bg rounded-md animate-pulse mx-1 mb-1"></div>
+          {/each}
+        {:else if tree.length === 0}
+          <p class="text-xs text-dim px-3 py-4">
+            아직 자료실에 등록된 문서가 없습니다.<br />
+            문서 상세 페이지에서 자료실 경로를 추가하세요.
+          </p>
+        {:else}
+          <nav>
+            {#each tree as node}
+              {#snippet treeNode(n, depth)}
+                {@const isActive = activePath === n.path}
+                {@const isParent = activePath?.startsWith(n.path + '/')}
+                {@const hasChildren = n.children.length > 0}
+                {@const isExpanded = expanded[n.path]}
+
+                <div class="flex items-center" style="padding-left: {depth * 16}px">
+                  {#if hasChildren}
+                    <button
+                      onclick={() => toggleExpand(n.path)}
+                      class="p-0.5 rounded hover:bg-surface-hover text-dim"
+                    >
+                      {#if isExpanded}
+                        <ChevronDown size={14} />
+                      {:else}
+                        <ChevronRight size={14} />
+                      {/if}
+                    </button>
+                  {:else}
+                    <span class="w-5"></span>
+                  {/if}
+
+                  <button
+                    onclick={() => navigate(n.path)}
+                    class="flex-1 flex items-center justify-between px-2 py-1.5 rounded-md text-sm transition-colors
+                      {isActive
+                      ? 'bg-accent/15 text-accent'
+                      : isParent
+                        ? 'text-text'
+                        : 'text-dim hover:bg-surface-hover hover:text-text'}"
+                  >
+                    <span class="truncate">{n.name}</span>
+                    <span class="text-xs text-dim shrink-0 ml-2">{n.count}</span>
+                  </button>
+                </div>
+
+                {#if hasChildren && isExpanded}
+                  {#each n.children as child}
+                    {@render treeNode(child, depth + 1)}
+                  {/each}
+                {/if}
+              {/snippet}
+              {@render treeNode(node, 0)}
+            {/each}
+          </nav>
+        {/if}
+      </div>
+    </aside>
+
+    <!-- 오른쪽: 문서 목록 (7/12) -->
+    <main class="lg:col-span-7 xl:col-span-8">
+      <!-- 컨트롤 바 -->
+      <div class="flex flex-wrap items-center gap-2 mb-4">
+        <!-- 정렬 -->
+        <select
+          value={activeSort}
+          onchange={(e) => setSort(e.target.value)}
+          class="px-2 py-1.5 bg-surface border border-default rounded text-xs text-text outline-none focus:border-accent"
+        >
+          {#each SORT_OPTIONS as opt}
+            <option value={opt.value}>{opt.label}</option>
+          {/each}
+        </select>
+
+        <!-- 제목 검색 -->
+        <input
+          type="text"
+          value={searchInput}
+          oninput={handleSearchInput}
+          placeholder="제목 검색..."
+          class="flex-1 min-w-[120px] max-w-[240px] px-2 py-1.5 bg-surface border border-default rounded text-xs text-text outline-none focus:border-accent"
+        />
+
+        <span class="text-xs text-dim ml-auto">{total}건</span>
+      </div>
+
+      <!-- 문서 목록 -->
+      {#if docsLoading}
+        <div class="space-y-2">
+          {#each Array(5) as _}
+            <Skeleton h="h-20" rounded="lg" />
+          {/each}
+        </div>
+      {:else if docs.length === 0}
+        <EmptyState
+          icon={FolderOpen}
+          title={activePath ? `"${activePath}" 경로에 문서가 없습니다` : '자료실이 비어 있습니다'}
+          description="문서 상세 페이지에서 자료실 경로를 추가하세요."
+        />
+      {:else}
+        <div class="space-y-2">
+          {#each docs as doc (doc.id)}
+            <div class="bg-surface border border-default rounded-lg hover:border-accent/50 transition-colors">
+              <!-- 카드 상단: 문서 정보 -->
+              <a
+                href="/documents/{doc.id}"
+                class="flex items-start gap-3 p-3"
+              >
+                <div class="shrink-0 mt-0.5 text-dim">
+                  <FormatIcon format={doc.file_format} size={18} />
+                </div>
+                <div class="flex-1 min-w-0">
+                  <p class="text-sm font-medium truncate hover:text-accent">{doc.title || '제목 없음'}</p>
+                  <div class="flex items-center gap-2 mt-0.5 text-[11px] text-dim">
+                    <span>{doc.file_format}</span>
+                    {#if doc.updated_at}
+                      <span class="text-faint">·</span>
+                      <span>
+                        {new Date(doc.updated_at).toLocaleDateString('ko-KR', {
+                          year: 'numeric',
+                          month: 'short',
+                          day: 'numeric',
+                        })}
+                      </span>
+                    {/if}
+                  </div>
+                </div>
+              </a>
+
+              <!-- 카드 하단: 액션 버튼 -->
+              <div class="flex items-center gap-1.5 px-3 pb-2">
+                {#if getEditUrl(doc)}
+                  <a
+                    href={getEditUrl(doc)}
+                    target="_blank"
+                    rel="noopener noreferrer"
+                    class="inline-flex items-center gap-1 px-2 py-1 text-[11px] text-dim hover:text-accent hover:bg-surface-hover rounded transition-colors"
+                  >
+                    <ExternalLink size={12} /> 편집
+                  </a>
+                {/if}
+                <button
+                  type="button"
+                  onclick={() => downloadOriginal(doc)}
+                  class="inline-flex items-center gap-1 px-2 py-1 text-[11px] text-dim hover:text-accent hover:bg-surface-hover rounded transition-colors"
+                >
+                  <Download size={12} /> 원본
+                </button>
+                {#if doc.preview_status === 'ready'}
+                  <button
+                    type="button"
+                    onclick={() => downloadPdf(doc)}
+                    class="inline-flex items-center gap-1 px-2 py-1 text-[11px] text-dim hover:text-accent hover:bg-surface-hover rounded transition-colors"
+                  >
+                    <FileText size={12} /> PDF
+                  </button>
+                {:else if doc.preview_status === 'processing'}
+                  <span class="inline-flex items-center gap-1 px-2 py-1 text-[11px] text-faint" title="미리보기 생성 중">
+                    <FileText size={12} /> PDF 생성 중
+                  </span>
+                {/if}
+              </div>
+            </div>
+          {/each}
+        </div>
+
+        <!-- 페이지네이션 -->
+        {#if totalPages > 1}
+          <div class="flex items-center justify-center gap-2 mt-6">
+            {#if activePage > 1}
+              <Button
+                variant="ghost"
+                size="sm"
+                onclick={() => {
+                  const p = new URLSearchParams($page.url.searchParams);
+                  p.set('page', String(activePage - 1));
+                  goto(`/library?${p}`, { noScroll: true });
+                }}
+              >
+                이전
+              </Button>
+            {/if}
+            <span class="text-xs text-dim">{activePage} / {totalPages}</span>
+            {#if activePage < totalPages}
+              <Button
+                variant="ghost"
+                size="sm"
+                onclick={() => {
+                  const p = new URLSearchParams($page.url.searchParams);
+                  p.set('page', String(activePage + 1));
+                  goto(`/library?${p}`, { noScroll: true });
+                }}
+              >
+                다음
+              </Button>
+            {/if}
+          </div>
+        {/if}
+      {/if}
+    </main>
+  </div>
+</div>
diff --git a/migrations/114_library_user_tags_gin.sql b/migrations/114_library_user_tags_gin.sql
new file mode 100644
index 0000000..ecf6904
--- /dev/null
+++ b/migrations/114_library_user_tags_gin.sql
@@ -0,0 +1,4 @@
+-- 자료실: user_tags JSONB GIN 인덱스 (경로 containment 쿼리 가속)
+CREATE INDEX IF NOT EXISTS idx_documents_user_tags_gin
+ON documents USING GIN (user_tags jsonb_path_ops)
+WHERE user_tags IS NOT NULL;