diff --git a/B07_DesignDetail/B07_DesignDetail_UI_Page.ts b/B07_DesignDetail/B07_DesignDetail_UI_Page.ts
index 4ee7d0a34..368f5c4a3 100644
--- a/B07_DesignDetail/B07_DesignDetail_UI_Page.ts
+++ b/B07_DesignDetail/B07_DesignDetail_UI_Page.ts
@@ -25,6 +25,7 @@ import {
   buildCrossLayoutControls,
   buildDesignInfoPanel,
   buildDrawingSidePanel,
+  foldedGroups,
   isCrossSheet,
 } from "./B07_DesignDetail_UI_Panels";
 import { workflowSteps } from "../A00_Common/b_page_scaffold";
@@ -91,6 +92,8 @@ let reopenCrossSheet: number | undefined;
 
 export async function renderB07DesignDetail(root: HTMLElement): Promise<void> {
   const projectId = localStorage.getItem(CURRENT_PROJECT_ID_KEY);
+  // 311 다시 세우면 옛 목록 접힘 그대로 — 기다리기 전에 읽음(처음 들어오면 B07 목록이 없어 기본값)
+  const folded = foldedGroups(root);
   let workflowState: WorkflowState | undefined;
   let drawings: DesignDrawingItem[] = [];
   let drawingError: string | undefined;
@@ -565,6 +568,7 @@ export async function renderB07DesignDetail(root: HTMLElement): Promise<void> {
         }
       : undefined,
     crossLayoutSlot,
+    folded,
   );
   drawingListEl = drawingPanel;
   const confirmActions = document.createElement("div");
@@ -608,7 +612,7 @@ export async function renderB07DesignDetail(root: HTMLElement): Promise<void> {
   layout.root.classList.add("b07-design-layout");
   root.replaceChildren(layout.root);
 
-  // 페이지 진입 시 첫 도면(종단도)을 자동 선택 — 빈 CAD 화면 방지.
+  // 페이지 진입 시 첫 도면(표지 · 311)을 자동 선택 — 빈 CAD 화면 방지.
   // CAD가 아직 준비 전이면 cad.load 가 붙들고 있다가 ready 때 보낸다.
   if (drawings.length > 0) {
     const crossSheets = drawings.filter(isCrossSheet);
@@ -618,7 +622,9 @@ export async function renderB07DesignDetail(root: HTMLElement): Promise<void> {
     const reopen = drawings.findIndex((item) => item.id === reopenId);
     reopenDrawingId = undefined;
     reopenCrossSheet = undefined;
-    const first = Math.max(reopen, 0);
+    // 311 기억한 장이 없으면 표지
+    const cover = drawings.findIndex((item) => item.kind === "cover");
+    const first = reopen >= 0 ? reopen : Math.max(cover, 0);
     void openTab(drawings[first]).then(() => {
       // 첫 장을 띄운 뒤에 나머지를 받는다 — 진입 속도를 뺏지 않는다.
       void prefetchAllDrawings();
diff --git a/B07_DesignDetail/B07_DesignDetail_UI_Panels.ts b/B07_DesignDetail/B07_DesignDetail_UI_Panels.ts
index d19228411..a9eb48d9f 100644
--- a/B07_DesignDetail/B07_DesignDetail_UI_Panels.ts
+++ b/B07_DesignDetail/B07_DesignDetail_UI_Panels.ts
@@ -39,6 +39,19 @@ export const DRAWING_GROUPS: readonly {
   { label: "토적도(유토곡선)", kind: "mass_haul" },
 ];
 
+/** 311 기본 접힘 묶음 — 그 밖 묶음(토적도 등)은 기본 펼침. */
+const FOLDED_KINDS = new Set(["plan", "longitudinal", "cross"]);
+
+/** 311 지금 목록의 묶음 접힘(kind → 접힘) — 화면을 다시 세울 때 이어 받음 · B07 목록이 없으면 빈 것. */
+export function foldedGroups(root: ParentNode): Map<string, boolean> {
+  return new Map(
+    [...root.querySelectorAll<HTMLElement>(".b07-drawing-group")].map((section) => [
+      section.dataset.kind ?? "",
+      section.classList.contains("is-collapsed"),
+    ]),
+  );
+}
+
 /** B06 확정 산출물 기반 도면 목록 패널. */
 export function buildDrawingSidePanel(
   drawings: DesignDrawingItem[],
@@ -48,7 +61,10 @@ export function buildDrawingSidePanel(
   plan?: PlanManageControls,
   /** 횡단도 묶음 맨 아래에 붙일 자리(153-1 장 배치 칸) — 내용은 화면 조립이 도면을 열 때마다 채움. */
   crossTools?: HTMLElement,
+  /** 311 다시 세울 때 옛 접힘(`foldedGroups`) — 없는 묶음은 기본값. */
+  folded = new Map<string, boolean>(),
 ): HTMLDivElement {
+  const isFolded = (kind: string): boolean => folded.get(kind) ?? FOLDED_KINDS.has(kind);
   const panel = document.createElement("div");
   panel.className = "b07-drawing-list";
   const heading = document.createElement("div");
@@ -95,7 +111,12 @@ export function buildDrawingSidePanel(
       // 종류를 다 지워도 묶음은 남긴다 — 그 안에서 다시 더한다.
       const plans = drawings.filter((item) => item.kind === "plan");
       panel.append(
-        buildPlanSection(plans, drawingButton, plan ? () => openPlanManager(plan) : undefined),
+        buildPlanSection(
+          plans,
+          drawingButton,
+          plan ? () => openPlanManager(plan) : undefined,
+          isFolded("plan"),
+        ),
       );
       continue;
     }
@@ -133,7 +154,7 @@ export function buildDrawingSidePanel(
       continue;
     }
     // 컨테이너 = 좌측 패널 공용 카드(269 · B05/B06 「구조물 배치」 양식).
-    const section = createPanelCard(`${group.label} ${items.length}`);
+    const section = createPanelCard(`${group.label} ${items.length}`, isFolded(group.kind ?? ""));
     section.classList.add("b07-drawing-group");
     if (group.kind) section.dataset.kind = group.kind;
     if (cross) {
diff --git a/B07_DesignDetail/B07_DesignDetail_UI_PlanKinds.ts b/B07_DesignDetail/B07_DesignDetail_UI_PlanKinds.ts
index 3d04ef741..d1f10c410 100644
--- a/B07_DesignDetail/B07_DesignDetail_UI_PlanKinds.ts
+++ b/B07_DesignDetail/B07_DesignDetail_UI_PlanKinds.ts
@@ -257,9 +257,10 @@ export function buildPlanSection(
   items: DesignDrawingItem[],
   makeButton: (drawing: DesignDrawingItem, label: string) => HTMLButtonElement,
   onManage?: () => void,
+  collapsed = false,
 ): HTMLElement {
   // 컨테이너 = 좌측 패널 공용 카드(269)
-  const section = createPanelCard(`평면도 ${items.length}`);
+  const section = createPanelCard(`평면도 ${items.length}`, collapsed);
   section.classList.add("b07-drawing-group", "b07-plan");
   section.dataset.kind = "plan";
 
diff --git a/resources/tester/helper_311_panel_folded.cjs b/resources/tester/helper_311_panel_folded.cjs
new file mode 100644
index 000000000..4b997e9bb
--- /dev/null
+++ b/resources/tester/helper_311_panel_folded.cjs
@@ -0,0 +1,256 @@
+/* 311 좌측 패널 기본 접힘 헬퍼 — B05 「계획노선」 · B06 「횡단 보기 설정」(한 벌 패널 `design_panel`)과
+ * B07 도면 목록(평면도 · 종단도 · 횡단도)을 가짜 DOM 위에 세워 첫 그림 접힘 · 편 뒤 다시 그림 유지를 본다.
+ * 결과는 JSON 한 벌. 꼴은 `helper_design_view_parity.cjs` 와 같음.
+ */
+const fs = require("fs");
+const path = require("path");
+const ts = require(path.join(__dirname, "..", "..", "config", "node_modules", "typescript"));
+
+const ROOT = path.join(__dirname, "..", "..");
+const cache = new Map();
+
+// ── 화면 그릇 흉내 — 요소 · 클래스 · 속성 · 글자 · 자식 ──────────────────────────
+class FakeNode {
+  constructor(tag) {
+    this.tagName = tag;
+    this.children = [];
+    this.parent = null;
+    this.dataset = {};
+    this.style = {};
+    this.attrs = {};
+    this._text = "";
+    this._classes = new Set();
+    this.hidden = false;
+    this.disabled = false;
+    this.title = "";
+    this.listeners = {};
+    const self = this;
+    this.classList = {
+      add: (...n) => n.forEach((x) => self._classes.add(x)),
+      remove: (...n) => n.forEach((x) => self._classes.delete(x)),
+      toggle: (n, f) => {
+        const on = f === undefined ? !self._classes.has(n) : !!f;
+        on ? self._classes.add(n) : self._classes.delete(n);
+        return on;
+      },
+      contains: (n) => self._classes.has(n),
+    };
+  }
+  set className(v) {
+    this._classes = new Set(String(v).split(/\s+/).filter(Boolean));
+  }
+  get className() {
+    return [...this._classes].join(" ");
+  }
+  set textContent(v) {
+    this._text = String(v);
+    this.children.forEach((c) => (c.parent = null));
+    this.children = [];
+  }
+  get textContent() {
+    return this._text + this.children.map((c) => c.textContent).join("");
+  }
+  _adopt(kid) {
+    const node =
+      typeof kid === "string" ? Object.assign(new FakeNode("#text"), { _text: kid }) : kid;
+    if (node.parent) node.parent.children = node.parent.children.filter((c) => c !== node);
+    node.parent = this;
+    return node;
+  }
+  append(...kids) {
+    kids.forEach((k) => this.children.push(this._adopt(k)));
+  }
+  prepend(...kids) {
+    this.children.unshift(...kids.map((k) => this._adopt(k)));
+  }
+  insertBefore(node, ref) {
+    const adopted = this._adopt(node);
+    const at = this.children.indexOf(ref);
+    if (at < 0) this.children.push(adopted);
+    else this.children.splice(at, 0, adopted);
+  }
+  replaceChildren(...kids) {
+    this.children = [];
+    this.append(...kids);
+  }
+  setAttribute(k, v) {
+    this.attrs[k] = String(v);
+  }
+  removeAttribute(k) {
+    delete this.attrs[k];
+    if (k === "title") this.title = "";
+  }
+  addEventListener(type, handler) {
+    (this.listeners[type] ||= []).push(handler);
+  }
+  click() {
+    if (this.disabled) return;
+    (this.listeners.click || []).forEach((h) => h({ target: this }));
+  }
+  querySelector(selector) {
+    return this.querySelectorAll(selector)[0] ?? null;
+  }
+  querySelectorAll(selector) {
+    const cls = selector.slice(1);
+    const out = [];
+    const walk = (n) =>
+      n.children.forEach((k) => {
+        if (k.classList && k.classList.contains(cls)) out.push(k);
+        walk(k);
+      });
+    walk(this);
+    return out;
+  }
+}
+// 공용 attachCollapsible 이 쓰는 closest(`.클래스` 하나)
+FakeNode.prototype.closest = function (selector) {
+  for (let n = this; n; n = n.parent)
+    if (n.classList && n.classList.contains(selector.slice(1))) return n;
+  return null;
+};
+globalThis.document = { createElement: (tag) => new FakeNode(tag) };
+/** 제목 누름 — 패널 뿌리에 걸린 공용 위임 손잡이로 올려 보냄(가짜 DOM 은 거품이 없음). */
+const press = (root, section) => {
+  const target = section.querySelector(".ui-collapsible__title");
+  (root.listeners.click || []).forEach((h) => h({ target }));
+};
+
+const node = (tag = "div") => new FakeNode(tag);
+const STUBS = {
+  "@ui/ui_template_locale": {
+    ui_locales: new Proxy({}, { get: (_, k) => [String(k)] }),
+    currentLanguageIndex: 0,
+  },
+  "@ui/ui_template_elements": {
+    createButton: ({ label }) => Object.assign(node("button"), { _text: label }),
+    createInputField: () => ({ root: node(), input: node("input") }),
+    createSelectField: () => ({ root: node(), select: { value: "" } }),
+    showToast: () => undefined,
+  },
+  "@ui/ui_template_checkbox": { createCheckbox: () => ({ root: node("label"), input: {} }) },
+  "../B05_Profile/B05_Profile_UI_Structures_Fields": { stationFields: () => ({ wrap: node() }) },
+  "./B07_DesignDetail_UI_PlanManage": { openPlanManager: () => undefined },
+  "./B07_DesignDetail_Api_Fetch": {},
+  "./B06_Section_UI_Page_Common": { L: (key) => key },
+};
+
+function loadTs(file) {
+  const full = path.resolve(file);
+  if (cache.has(full)) return cache.get(full);
+  const js = ts.transpileModule(fs.readFileSync(full, "utf8"), {
+    compilerOptions: { module: ts.ModuleKind.CommonJS, target: ts.ScriptTarget.ES2020 },
+  }).outputText;
+  const box = { exports: {} };
+  cache.set(full, box.exports);
+  const localRequire = (request) => {
+    if (STUBS[request]) return STUBS[request];
+    if (request === "@ui/ui_template_collapsible")
+      return loadTs(path.join(ROOT, "ui_template", "ui_template_collapsible.ts"));
+    if (request.endsWith(".css")) return {};
+    if (request.startsWith(".")) return loadTs(`${path.resolve(path.dirname(full), request)}.ts`);
+    return require(request);
+  };
+  new Function("exports", "module", "require", js)(box.exports, box, localRequire);
+  cache.set(full, box.exports);
+  return box.exports;
+}
+
+const out = {};
+const titleOf = (n) => n.children.find((c) => c.tagName === "h3")?.textContent ?? "";
+const folds = (root) =>
+  Object.fromEntries(
+    root
+      .querySelectorAll(".ui-collapsible")
+      .map((s) => [titleOf(s), s.classList.contains("is-collapsed")]),
+  );
+
+// ── B05 · B06 한 벌 패널 ───────────────────────────────────────────────────────
+const design = loadTs(path.join(ROOT, "A00_Common", "design", "design_panel.ts"));
+loadTs(path.join(ROOT, "B05_Profile", "B05_Profile_UI_Panel_Sections.ts"));
+loadTs(path.join(ROOT, "B06_Section", "B06_Section_UI_Page_Panel.ts"));
+const text = (t) => Object.assign(node(), { _text: t });
+const run = { run: () => undefined };
+const panel = design.createDesignPanel(
+  {
+    projectId: "p",
+    parts: {
+      structures: { root: node("section"), listRoot: node() },
+      settings: { nodes: [text("a")] },
+      route: {
+        plannedRouteButton: text("plan"),
+        selectedNodes: [text("sel")],
+        bindSelectedRoot: () => undefined,
+      },
+      crossView: { row: text("cross-row") },
+      standardSlot: text("std"),
+    },
+    dock: { reset: run, save: run, confirm: run, switchView: run },
+  },
+  "profile",
+);
+const byTitle = (title) =>
+  panel.root.querySelectorAll(".ui-collapsible").find((s) => titleOf(s) === title);
+out.profileFirst = folds(panel.root);
+const route = byTitle("계획노선");
+press(panel.root, route); // 사용자가 폄(공용 attachCollapsible)
+panel.setView("cross");
+out.crossFirst = folds(panel.root);
+press(panel.root, byTitle("B06_View_Title"));
+panel.setView("profile");
+panel.setView("cross");
+out.afterRedraw = folds(panel.root);
+out.sameRouteNode = byTitle("계획노선") === route;
+
+// ── B07 도면 목록 ─────────────────────────────────────────────────────────────
+const b07 = loadTs(path.join(ROOT, "B07_DesignDetail", "B07_DesignDetail_UI_Panels.ts"));
+const d = (id, kind) => ({ id, kind, label: id, confirmed: false });
+const drawings = [
+  d("longitudinal", "longitudinal"),
+  d("longitudinal_2", "longitudinal"),
+  d("cross_1", "cross"),
+  d("cross_2", "cross"),
+  d("plan_a", "plan"),
+  d("cover", "cover"),
+  d("cross_standard", "cross_standard"),
+  d("mass_haul", "mass_haul"),
+  d("mass_haul_2", "mass_haul"),
+];
+const groups = (p) =>
+  Object.fromEntries(
+    p
+      .querySelectorAll(".b07-drawing-group")
+      .map((s) => [s.dataset.kind, s.classList.contains("is-collapsed")]),
+  );
+const fresh = node();
+out.b07EntryFolded = [...b07.foldedGroups(fresh)];
+const first = b07.buildDrawingSidePanel(
+  drawings,
+  () => undefined,
+  undefined,
+  false,
+  undefined,
+  undefined,
+  b07.foldedGroups(fresh),
+);
+out.b07First = groups(first);
+const host = node();
+host.append(first);
+first
+  .querySelectorAll(".b07-drawing-group")
+  .find((s) => s.dataset.kind === "cross")
+  .classList.remove("is-collapsed");
+first
+  .querySelectorAll(".b07-drawing-group")
+  .find((s) => s.dataset.kind === "mass_haul")
+  .classList.add("is-collapsed");
+const again = b07.buildDrawingSidePanel(
+  drawings,
+  () => undefined,
+  undefined,
+  false,
+  undefined,
+  undefined,
+  b07.foldedGroups(host),
+);
+out.b07Redraw = groups(again);
+process.stdout.write(JSON.stringify(out));
diff --git a/resources/tester/test_269_panel_form.py b/resources/tester/test_269_panel_form.py
index 33ff60bd2..c2c5cc4b8 100644
--- a/resources/tester/test_269_panel_form.py
+++ b/resources/tester/test_269_panel_form.py
@@ -82,8 +82,8 @@ def test_공용_카드_함수():
 
 
 def test_B07_컨테이너_공용_카드_도면_단추_공용_꼴():
-    assert "createPanelCard(`${group.label} ${items.length}`)" in B07_PANELS
-    assert "createPanelCard(`평면도 ${items.length}`)" in B07_PLAN
+    assert "createPanelCard(`${group.label} ${items.length}`, isFolded(" in B07_PANELS
+    assert "createPanelCard(`평면도 ${items.length}`, collapsed)" in B07_PLAN
     for src in (B07_PANELS, B07_PLAN):
         assert "ui-collapsible ui-sidebar-section" not in src  # 손으로 짠 카드 없음
     assert B07_PANELS.count('"b07-drawing-button ui-panel-btn"') == 2
@@ -149,7 +149,7 @@ def test_B05_칸_틀_두_보기_모두_공용_양식():
 
 def test_B08_B09_카드_공용_카드():
     assert "createPanelCard(L(title))" in B08_OPTIONS
-    assert 'createPanelCard("데이터 점검")' in B09_SHELL
+    assert 'createPanelCard("데이터 점검", true)' in B09_SHELL
     for src in (B08_OPTIONS, B09_SHELL):
         assert "ui-sidebar-card" not in src
 
diff --git a/resources/tester/test_311_panel_folded.py b/resources/tester/test_311_panel_folded.py
new file mode 100644
index 000000000..66aeb65fd
--- /dev/null
+++ b/resources/tester/test_311_panel_folded.py
@@ -0,0 +1,101 @@
+# -*- coding: utf-8 -*-
+"""311 좌측 패널 기본 접힘 · B07 첫 쪽 = 표지 (요구 204).
+
+못박는 것
+  - 기본 접힘 = B09 「데이터 점검」 · 「공기 옵션」 / B07 「평면도」 · 「종단도」 · 「횡단도」 /
+    B06 「횡단 보기 설정」 / B05 「계획노선」 · 다른 컨테이너 기본값 그대로.
+  - 쪽 안에서 편 것은 다시 그려도 그대로 — B05 · B06 = 한 벌 패널이 칸을 한 번만 세움 · B07 = 다시 세울 때
+    옛 목록 접힘을 이어 받음 · B09 = 좌측 패널을 쪽 그릴 때 한 번만 세움.
+  - B07 처음 들어가면 표지 — 고른 장 기억(모듈 값 `reopenDrawingId` · `reopenCrossSheet`)이 있으면 그 장.
+
+Node 헬퍼 `helper_311_panel_folded.cjs` 가 가짜 DOM 위에서 B05 · B06 · B07 패널을 돌림.
+"""
+
+import json
+import os
+import subprocess
+from pathlib import Path
+
+import pytest
+
+HERE = os.path.dirname(os.path.abspath(__file__))
+ROOT = Path(HERE).parents[1]
+
+
+def _read(rel: str) -> str:
+    return (ROOT / rel).read_text(encoding="utf-8")
+
+
+@pytest.fixture(scope="module")
+def out():
+    proc = subprocess.run(
+        ["node", os.path.join(HERE, "helper_311_panel_folded.cjs")],
+        capture_output=True,
+        text=True,
+        encoding="utf-8",
+        timeout=60,
+    )
+    assert proc.returncode == 0, proc.stderr
+    return json.loads(proc.stdout)
+
+
+def test_B05_B06_첫_그림_접힘(out):
+    assert out["profileFirst"] == {
+        "페이지 설정": True,
+        "계획노선": True,
+        "선택 포인트 상세 설정": False,
+    }
+    assert out["crossFirst"]["B06_View_Title"] is True
+    assert out["crossFirst"]["B06_Std_Title"] is True  # 옛 기본 접힘 그대로
+
+
+def test_B05_B06_편_뒤_다시_그림_유지(out):
+    assert out["crossFirst"]["계획노선"] is False  # 편 것 → 보기 바꿔도 그대로
+    assert out["afterRedraw"]["계획노선"] is False
+    assert out["afterRedraw"]["B06_View_Title"] is False
+    assert out["sameRouteNode"] is True
+
+
+def test_B07_첫_그림_접힘(out):
+    assert out["b07EntryFolded"] == []  # 들어올 때 = 라우터가 비운 그릇 → 기본값
+    assert out["b07First"] == {
+        "plan": True,
+        "longitudinal": True,
+        "cross": True,
+        "mass_haul": False,
+    }
+
+
+def test_B07_다시_세워도_접힘_이어_받음(out):
+    assert out["b07Redraw"] == {
+        "plan": True,
+        "longitudinal": True,
+        "cross": False,
+        "mass_haul": True,
+    }
+
+
+def test_B07_다시_세우기는_옛_목록을_기다리기_전에_읽음():
+    page = _read("B07_DesignDetail/B07_DesignDetail_UI_Page.ts")
+    body = page[page.index("export async function renderB07DesignDetail(") :]
+    assert body.index("const folded = foldedGroups(root);") < body.index("await ")
+    assert "crossLayoutSlot,\n    folded,\n  );" in body.replace("\r\n", "\n")
+
+
+def test_B07_첫_장은_표지_기억_있으면_그_장():
+    page = _read("B07_DesignDetail/B07_DesignDetail_UI_Page.ts")
+    assert 'const cover = drawings.findIndex((item) => item.kind === "cover");' in page
+    assert "const first = reopen >= 0 ? reopen : Math.max(cover, 0);" in page
+
+
+def test_B09_기본_접힘_좌측은_한_번만_세움():
+    shell = _read("B09_Estimation/B09_Estimation_UI_Shell.ts")
+    assert 'createPanelCard("데이터 점검", true)' in shell
+    assert 'createPanelCard("공기 옵션", true)' in _read(
+        "B09_Estimation/draft/B09_Draft_Schedule_Panel.ts"
+    )
+    # 다시 그림(show) 은 가운데 판만 바꿈 — 좌측 카드는 쪽 그릴 때 한 번
+    show = shell[shell.index("const show = (tab: TabId") : shell.index("const run = async (")]
+    assert "createPanelCard" not in show and "left." not in show
+    print_page = _read("B09_Estimation/draft/B09_Draft_Print_Page.ts")
+    assert 'createPanelCard("영역")' in print_page and 'createPanelCard("쪽 목록")' in print_page