diff --git a/frontend/src/routes/book/[id]/+page.svelte b/frontend/src/routes/book/[id]/+page.svelte
index 25be284..649edec 100644
--- a/frontend/src/routes/book/[id]/+page.svelte
+++ b/frontend/src/routes/book/[id]/+page.svelte
@@ -1,7 +1,7 @@
 <script>
-  // ASME 절-지식베이스: 유기적 단일-책 리더. parent 표준의 절-문서들을 한 권의 책처럼 탐색.
-  // 좌: Part-그룹 TOC / 우: 선택 절 본문 + breadcrumb + 이전/다음 + 양방향 백링크.
-  import { onMount } from 'svelte';
+  // ASME/법령 절-KB — 코드북·공부 리더 (r2). parent 표준/법령을 한 권의 책처럼.
+  // 좌 인덱스(Part/章→절/조) · 중 본문(MarkdownDoc=공식·표·이미지) · breadcrumb·이전다음·양방향 백링크.
+  import { onMount, tick } from 'svelte';
   import { page } from '$app/stores';
   import { goto } from '$app/navigation';
   import { api } from '$lib/api';
@@ -15,6 +15,7 @@
   let links = $state(null);
   let expanded = $state({});
   let loading = $state(false);
+  let q = $state('');
 
   let parts = $derived.by(() => {
     const out = [], idx = {};
@@ -25,8 +26,15 @@
     }
     return out;
   });
+  let visibleParts = $derived.by(() => {
+    const term = q.trim().toLowerCase();
+    if (!term) return parts;
+    return parts.map(g => ({ part: g.part, items: g.items.filter(c =>
+      (c.clause_code || '').toLowerCase().includes(term) || (c.title || '').toLowerCase().includes(term)) }))
+      .filter(g => g.items.length);
+  });
   let selMeta = $derived(clauses.find((c) => c.id === selectedId) || null);
-  const strip = (title, code) => (title || '').replace(code || '', '').trim();
+  const strip = (t, c) => (t || '').replace(c || '', '').replace(/^[(\s)]+|[(\s)]+$/g, '').trim();
 
   async function loadBook() {
     const r = await api(`/documents/${parentId}/clauses`);
@@ -41,21 +49,14 @@
     loading = true;
     selectedId = id;
     try {
-      const [d, l] = await Promise.all([
-        api(`/documents/${id}`),
-        api(`/documents/${id}/backlinks`)
-      ]);
-      clauseDoc = d;
-      links = l;
+      const [d, l] = await Promise.all([api(`/documents/${id}`), api(`/documents/${id}/backlinks`)]);
+      clauseDoc = d; links = l;
       const sel = clauses.find((c) => c.id === id);
       if (sel) expanded = { ...expanded, [sel.clause_part || '·']: true };
       goto(`/book/${parentId}?c=${id}`, { replaceState: true, keepFocus: true, noScroll: true });
-      window.scrollTo({ top: 0 });
-    } finally {
-      loading = false;
-    }
+      await tick(); window.scrollTo({ top: 0 });
+    } finally { loading = false; }
   }
-
   onMount(async () => {
     parentId = Number($page.params.id);
     await loadBook();
@@ -65,137 +66,144 @@
 </script>
 
 <div class="book">
-  <aside class="toc">
-    <a class="btitle" href={`/documents/${parentId}`}>{parentTitle || 'ASME 표준'}</a>
-    <div class="hint">절 {clauses.length}개 · 한 권의 책처럼 탐색</div>
-    {#each parts as g (g.part)}
-      <div class="part">
-        <button class="phead" onclick={() => (expanded = { ...expanded, [g.part]: !expanded[g.part] })}>
-          <span class="caret">{expanded[g.part] ? '▾' : '▸'}</span>
-          <span class="pname">{g.part}</span>
-          <span class="cnt">{g.items.length}</span>
-        </button>
-        {#if expanded[g.part]}
-          <ul>
-            {#each g.items as c (c.id)}
-              <li>
-                <button class="citem" class:active={c.id === selectedId} onclick={() => loadClause(c.id)}>
-                  <b>{c.clause_code}</b><span class="ct">{strip(c.title, c.clause_code)}</span>
-                </button>
-              </li>
-            {/each}
-          </ul>
+  <!-- top bar -->
+  <div class="bar">
+    <span class="brand">절-KB</span>
+    <span class="crumbs">{parentTitle} {#if selMeta}<b class="sep">›</b> {selMeta.clause_part} <b class="sep">›</b> <b>{links?.clause_code ?? selMeta.clause_code}</b>{/if}</span>
+    <div class="search"><input placeholder="절·조 번호 또는 키워드" bind:value={q} /></div>
+    <div class="tools"><span class="tool on">읽기</span><span class="tool">형광펜</span><span class="tool">노트</span><span class="tool">암기카드</span></div>
+  </div>
+
+  <div class="main">
+    <!-- left index -->
+    <aside class="idx">
+      <a class="btitle" href={`/documents/${parentId}`}>{parentTitle || '표준'}</a>
+      <div class="bmeta">절 {clauses.length} · 한 권의 책처럼 탐색</div>
+      {#each visibleParts as g (g.part)}
+        <div class="parttab" role="button" tabindex="0" onclick={() => (expanded = { ...expanded, [g.part]: !expanded[g.part] })}>
+          <span class="bar2"></span><span class="pname">{g.part}</span><span class="ct">{g.items.length}</span>
+        </div>
+        {#if expanded[g.part] || q.trim()}
+          {#each g.items as c (c.id)}
+            <div class="ci" class:on={c.id === selectedId} role="button" tabindex="0" onclick={() => loadClause(c.id)}>
+              <span class="no">{c.clause_code}</span><span class="tt">{strip(c.title, c.clause_code)}</span>
+            </div>
+          {/each}
+        {/if}
+      {/each}
+    </aside>
+
+    <!-- reader -->
+    <section class="read">
+      <div class="col">
+        {#if clauseDoc}
+          <div class="studybar">
+            <button class="sbtn" title="형광펜">▰</button>
+            <button class="sbtn" title="노트">✎</button>
+            <button class="sbtn" title="암기카드 추가">＋</button>
+          </div>
+          <div class="kicker"><span class="pth">{selMeta?.clause_part}</span></div>
+          <div class="h-no">{links?.clause_code ?? selMeta?.clause_code}</div>
+          <h1 class="h-title">{strip(clauseDoc.title, links?.clause_code ?? '')}</h1>
+
+          <div class="flow">
+            <button class="fl" disabled={!links?.prev} onclick={() => loadClause(links?.prev?.id)}>← {links?.prev?.clause_code ?? ''}</button>
+            <button class="fl next" disabled={!links?.next} onclick={() => loadClause(links?.next?.id)}>{links?.next?.clause_code ?? ''} →</button>
+          </div>
+
+          {#key clauseDoc.id}
+            <div class="docbody">
+              <MarkdownDoc documentId={clauseDoc.id} mdContent={clauseDoc.md_content ?? clauseDoc.extracted_text} mdStatus={null} class="prose prose-base max-w-none" />
+            </div>
+          {/key}
+
+          {#if links && (links.forward.length || links.back.length)}
+            <section class="conn">
+              {#if links.forward.length}
+                <div><h4>이 절이 참조 <span>{links.forward.length}</span></h4>
+                  <div class="chiprow">{#each links.forward as f}
+                    {#if f.doc_id}<button class="ref" onclick={() => loadClause(f.doc_id)}>{f.code}</button>
+                    {:else}<span class="ref dg" title="외부/미분해">{f.code}</span>{/if}
+                  {/each}</div></div>
+              {/if}
+              {#if links.back.length}
+                <div><h4>이 절을 참조 <span>{links.back.length}</span></h4>
+                  <div class="chiprow">{#each links.back as b}<button class="ref" onclick={() => loadClause(b.doc_id)}>{b.code}</button>{/each}</div></div>
+              {/if}
+            </section>
+          {/if}
+
+          <div class="pager">
+            <button class="pg" disabled={!links?.prev} onclick={() => loadClause(links?.prev?.id)}>
+              <div class="d">← 이전</div><div class="t"><span class="pno">{links?.prev?.clause_code ?? '—'}</span> {strip(links?.prev?.title, links?.prev?.clause_code)}</div></button>
+            <button class="pg next" disabled={!links?.next} onclick={() => loadClause(links?.next?.id)}>
+              <div class="d">다음 →</div><div class="t"><span class="pno">{links?.next?.clause_code ?? '—'}</span> {strip(links?.next?.title, links?.next?.clause_code)}</div></button>
+          </div>
+        {:else}
+          <p class="empty">{loading ? '불러오는 중…' : '왼쪽에서 절을 선택하세요'}</p>
         {/if}
       </div>
-    {/each}
-  </aside>
-
-  <main class="reader">
-    {#if clauseDoc}
-      <nav class="crumb">
-        <a href={`/documents/${parentId}`}>{parentTitle}</a>
-        <span class="sep">›</span><span>{selMeta?.clause_part}</span>
-        <span class="sep">›</span><b>{links?.clause_code ?? selMeta?.clause_code}</b>
-      </nav>
-      <div class="flow">
-        <button disabled={!links?.prev} onclick={() => loadClause(links?.prev?.id)}>
-          ← {links?.prev?.clause_code ?? ''}
-        </button>
-        <span class="flowmid">{selMeta?.clause_part}</span>
-        <button disabled={!links?.next} onclick={() => loadClause(links?.next?.id)}>
-          {links?.next?.clause_code ?? ''} →
-        </button>
-      </div>
-      <h1 class="ctitle">{clauseDoc.title}</h1>
-      {#key clauseDoc.id}
-        <MarkdownDoc
-          documentId={clauseDoc.id}
-          mdContent={clauseDoc.md_content ?? clauseDoc.extracted_text}
-          mdStatus={null}
-          class="prose prose-base max-w-none text-text"
-        />
-      {/key}
-
-      {#if links && (links.forward.length || links.back.length)}
-        <section class="xlinks">
-          {#if links.forward.length}
-            <div class="xcol">
-              <h3>이 절이 참조 <span>{links.forward.length}</span></h3>
-              <ul>
-                {#each links.forward as f}
-                  <li>
-                    {#if f.doc_id}
-                      <button class="xref" onclick={() => loadClause(f.doc_id)}>{f.code}</button>
-                    {:else}
-                      <span class="xref dangling" title="외부/미분해 참조">{f.code}</span>
-                    {/if}
-                    {#if f.title}<span class="xt">{strip(f.title, f.code)}</span>{/if}
-                  </li>
-                {/each}
-              </ul>
-            </div>
-          {/if}
-          {#if links.back.length}
-            <div class="xcol">
-              <h3>이 절을 참조 <span>{links.back.length}</span></h3>
-              <ul>
-                {#each links.back as b}
-                  <li>
-                    <button class="xref" onclick={() => loadClause(b.doc_id)}>{b.code}</button>
-                    {#if b.title}<span class="xt">{strip(b.title, b.code)}</span>{/if}
-                  </li>
-                {/each}
-              </ul>
-            </div>
-          {/if}
-        </section>
-      {/if}
-    {:else}
-      <p class="empty">{loading ? '로딩…' : '왼쪽에서 절을 선택하세요'}</p>
-    {/if}
-  </main>
+    </section>
+  </div>
 </div>
 
 <style>
-  .book { display: grid; grid-template-columns: 300px 1fr; gap: 0; min-height: 100vh; align-items: start; }
-  .toc { position: sticky; top: 0; max-height: 100vh; overflow-y: auto; border-right: 1px solid #e5e7eb; padding: 16px 12px; background: #fafafa; }
-  .btitle { display: block; font-weight: 700; font-size: 15px; color: #111827; text-decoration: none; line-height: 1.35; }
-  .btitle:hover { text-decoration: underline; }
-  .hint { font-size: 11.5px; color: #6b7280; margin: 4px 0 14px; }
-  .part { margin-bottom: 2px; }
-  .phead { display: flex; align-items: center; gap: 7px; width: 100%; background: none; border: 0; cursor: pointer; padding: 5px 6px; font-size: 13px; font-weight: 600; color: #374151; border-radius: 6px; }
-  .phead:hover { background: #f0f0f0; }
-  .caret { color: #9ca3af; width: 10px; }
-  .pname { flex: 1; text-align: left; }
-  .cnt { font-size: 11px; color: #9ca3af; }
-  .toc ul { list-style: none; margin: 0 0 4px; padding: 0 0 0 16px; }
-  .citem { display: block; width: 100%; text-align: left; background: none; border: 0; cursor: pointer; padding: 3px 7px; font-size: 12.5px; color: #4b5563; border-radius: 5px; line-height: 1.4; }
-  .citem:hover { background: #eef2ff; }
-  .citem.active { background: #e0e7ff; color: #1e3a8a; }
-  .citem b { color: #1d4ed8; margin-right: 5px; }
-  .citem.active b { color: #1e3a8a; }
-  .ct { color: #6b7280; }
-  .citem.active .ct { color: #334155; }
-  .reader { padding: 26px 34px 80px; max-width: 880px; }
-  .crumb { font-size: 12.5px; color: #6b7280; margin-bottom: 12px; }
-  .crumb a { color: #2563eb; text-decoration: none; }
-  .crumb a:hover { text-decoration: underline; }
-  .crumb .sep { margin: 0 6px; color: #cbd5e1; }
-  .flow { display: flex; align-items: center; justify-content: space-between; gap: 10px; margin-bottom: 18px; }
-  .flow button { background: #f3f4f6; border: 1px solid #e5e7eb; border-radius: 7px; padding: 6px 12px; font-size: 12.5px; color: #374151; cursor: pointer; }
-  .flow button:hover:not(:disabled) { background: #e5e7eb; }
-  .flow button:disabled { opacity: 0.4; cursor: default; }
-  .flowmid { font-size: 11.5px; color: #9ca3af; }
-  .ctitle { font-size: 22px; font-weight: 700; color: #111827; margin: 0 0 18px; letter-spacing: -0.2px; }
-  .xlinks { display: grid; grid-template-columns: 1fr 1fr; gap: 18px; margin-top: 40px; padding-top: 20px; border-top: 1px solid #e5e7eb; }
-  @media (max-width: 700px) { .book { grid-template-columns: 1fr; } .toc { position: static; max-height: none; } .xlinks { grid-template-columns: 1fr; } }
-  .xcol h3 { font-size: 13px; color: #374151; margin: 0 0 8px; }
-  .xcol h3 span { color: #9ca3af; font-weight: 400; }
-  .xcol ul { list-style: none; margin: 0; padding: 0; }
-  .xcol li { display: flex; align-items: baseline; gap: 7px; padding: 2px 0; font-size: 12.5px; }
-  .xref { background: #eff6ff; border: 1px solid #dbeafe; color: #1d4ed8; border-radius: 5px; padding: 1px 7px; font-size: 12px; font-weight: 600; cursor: pointer; white-space: nowrap; }
-  .xref:hover { background: #dbeafe; }
-  .xref.dangling { background: #f9fafb; border-color: #e5e7eb; color: #9ca3af; cursor: default; }
-  .xt { color: #6b7280; overflow: hidden; text-overflow: ellipsis; white-space: nowrap; }
-  .empty { color: #9ca3af; padding: 60px 0; text-align: center; }
+  :global(body) { background: var(--bg); }
+  .book { --paper:#fbfcf9; --serif:"Iowan Old Style","Palatino Linotype","Noto Serif KR",Georgia,serif;
+    display:flex; flex-direction:column; min-height:100vh; }
+  .bar { display:flex; align-items:center; gap:14px; height:50px; padding:0 18px; background:var(--paper); border-bottom:1px solid var(--border); }
+  .brand { font-weight:700; font-size:13.5px; color:var(--text); }
+  .crumbs { color:var(--text-dim); font-size:12.5px; overflow:hidden; text-overflow:ellipsis; white-space:nowrap; max-width:46%; }
+  .crumbs b { color:var(--text); font-weight:600; } .crumbs .sep { color:#c8d6c0; margin:0 5px; }
+  .search { margin-left:auto; }
+  .search input { width:280px; background:var(--surface); border:1px solid var(--border); border-radius:9px; padding:7px 12px; font-size:13px; color:var(--text); outline:none; }
+  .search input:focus { border-color:var(--accent); }
+  .tools { display:flex; gap:2px; }
+  .tool { font-size:12px; color:var(--text-dim); padding:6px 10px; border-radius:8px; border:1px solid transparent; cursor:pointer; }
+  .tool:hover { background:var(--surface); } .tool.on { background:#ecf0e8; border-color:var(--border); color:var(--accent-hover); font-weight:600; }
+
+  .main { display:flex; align-items:flex-start; flex:1; }
+  .idx { width:264px; flex-shrink:0; align-self:stretch; border-right:1px solid var(--border);
+    background:linear-gradient(180deg,#f6f8f3,#f1f4ec); padding:16px 10px 30px 16px; position:sticky; top:0; max-height:100vh; overflow:auto; }
+  .btitle { display:block; font-family:var(--serif); font-size:15.5px; font-weight:600; color:var(--text); text-decoration:none; line-height:1.32; }
+  .btitle:hover { text-decoration:underline; }
+  .bmeta { font-size:11px; color:#9aa090; margin:3px 0 14px; }
+  .parttab { display:flex; align-items:center; gap:8px; margin:11px 0 4px; padding:3px 4px; border-radius:6px; cursor:pointer;
+    font-size:11px; font-weight:700; letter-spacing:.5px; color:var(--text-dim); text-transform:uppercase; }
+  .parttab:hover { background:#fff; } .parttab .bar2 { width:3px; height:12px; border-radius:2px; background:var(--domain-engineering); }
+  .parttab .pname { flex:1; overflow:hidden; text-overflow:ellipsis; white-space:nowrap; } .parttab .ct { color:#9aa090; font-weight:600; letter-spacing:0; }
+  .ci { display:flex; gap:9px; align-items:baseline; padding:4px 9px; border-radius:7px; cursor:pointer; line-height:1.4; }
+  .ci .no { font-family:ui-monospace,Menlo,monospace; font-size:11px; color:var(--accent); font-weight:600; min-width:52px; white-space:nowrap; }
+  .ci .tt { font-size:12.5px; color:var(--text-dim); overflow:hidden; text-overflow:ellipsis; }
+  .ci:hover { background:#fff; }
+  .ci.on { background:#fff; box-shadow:inset 3px 0 0 var(--accent), 0 1px 2px rgba(35,41,31,.05); }
+  .ci.on .no { color:var(--accent-hover); font-weight:700; } .ci.on .tt { color:var(--text); font-weight:600; }
+
+  .read { flex:1; min-width:0; padding:34px 40px 80px; }
+  .col { max-width:680px; margin:0 auto; position:relative; }
+  .studybar { position:absolute; right:-30px; top:4px; display:flex; flex-direction:column; gap:6px; }
+  .sbtn { width:34px; height:34px; border-radius:9px; border:1px solid var(--border); background:var(--paper); color:var(--text-dim); font-size:13px; cursor:pointer; }
+  .sbtn:hover { background:var(--surface); color:var(--accent-hover); }
+  .kicker { margin-bottom:5px; } .kicker .pth { font-size:11.5px; color:#9aa090; font-weight:600; letter-spacing:.3px; }
+  .h-no { font-family:ui-monospace,Menlo,monospace; font-size:13px; color:var(--accent); font-weight:700; letter-spacing:.5px; }
+  .h-title { font-family:var(--serif); font-size:26px; line-height:1.24; font-weight:600; margin:2px 0 14px; letter-spacing:-.2px; color:var(--text); }
+  .flow { display:flex; justify-content:space-between; gap:8px; margin-bottom:18px; }
+  .flow .fl { font-size:11.5px; color:var(--text-dim); background:var(--surface); border:1px solid var(--border); border-radius:8px; padding:5px 11px; cursor:pointer; }
+  .flow .fl:hover:not(:disabled) { background:#ecf0e8; } .flow .fl:disabled { opacity:.35; cursor:default; }
+  .docbody { font-size:15.5px; }
+  .docbody :global(.prose) { color:#2a3024; line-height:1.78; }
+  .docbody :global(.prose h1), .docbody :global(.prose h2), .docbody :global(.prose h3) { font-family:var(--serif); }
+  .docbody :global(a) { color:var(--accent-hover); }
+  .conn { margin-top:34px; padding-top:18px; border-top:1px solid var(--border); display:grid; grid-template-columns:1fr 1fr; gap:22px; }
+  .conn h4 { font-size:11px; font-weight:700; color:var(--text-dim); letter-spacing:.4px; margin:0 0 9px; } .conn h4 span { color:#9aa090; font-weight:500; }
+  .chiprow { display:flex; flex-wrap:wrap; gap:5px; }
+  .ref { font-family:ui-monospace,Menlo,monospace; font-size:11.5px; font-weight:600; color:var(--accent-hover); background:#eef4ec; border:1px solid #d9e6d8; border-radius:6px; padding:2px 8px; cursor:pointer; }
+  .ref:hover { background:#e2efe0; } .ref.dg { color:#9aa090; background:var(--surface); border-color:var(--border); cursor:default; }
+  .pager { display:flex; gap:10px; margin-top:30px; }
+  .pg { flex:1; text-align:left; border:1px solid var(--border); border-radius:11px; padding:11px 14px; background:var(--paper); cursor:pointer; }
+  .pg.next { text-align:right; } .pg:hover:not(:disabled) { border-color:#cfd7c6; background:#fff; } .pg:disabled { opacity:.4; cursor:default; }
+  .pg .d { font-size:10.5px; color:#9aa090; } .pg .t { font-size:12.5px; color:var(--text-dim); font-weight:600; margin-top:1px; overflow:hidden; text-overflow:ellipsis; white-space:nowrap; }
+  .pg .pno { font-family:ui-monospace,Menlo,monospace; color:var(--accent); }
+  .empty { color:#9aa090; text-align:center; padding:80px 0; }
+  @media(max-width:820px){ .idx{display:none} .read{padding:24px 18px} .conn{grid-template-columns:1fr} .studybar{display:none} .crumbs{max-width:30%} .search input{width:150px} }
 </style>