diff --git a/A00_Common/spreadsheet/spreadsheet_cellstyle.ts b/A00_Common/spreadsheet/spreadsheet_cellstyle.ts
index 28b2db92..375998a7 100644
--- a/A00_Common/spreadsheet/spreadsheet_cellstyle.ts
+++ b/A00_Common/spreadsheet/spreadsheet_cellstyle.ts
@@ -44,7 +44,7 @@ export interface ResolvedBorders {
   오른?: BorderSide;
 }
 
-/** `서식` 표 번호 — 칸 → 행 → 열 → 0(기본) 차례(칸 안의 계약 주석과 같음). */
+/** `서식` 표 번호 — 칸 → 행 → 열 → 시트 `기본.서식` → 0(기본) 차례(칸 안의 계약 주석과 같음). */
 export function styleIndexAt(sheet: Sheet, r: number, c: number, key: string): number {
   const cell = sheet.칸[key];
   if (cell?.서식 !== undefined) return cell.서식;
@@ -52,6 +52,7 @@ export function styleIndexAt(sheet: Sheet, r: number, c: number, key: string): n
   if (rowFmt !== undefined) return rowFmt;
   const colFmt = sheet.열?.[colName(c)]?.서식;
   if (colFmt !== undefined) return colFmt;
+  if (sheet.기본?.서식 !== undefined) return sheet.기본.서식;
   return 0;
 }
 
diff --git a/A00_Common/spreadsheet/spreadsheet_fill.ts b/A00_Common/spreadsheet/spreadsheet_fill.ts
index 556d8033..2c33275c 100644
--- a/A00_Common/spreadsheet/spreadsheet_fill.ts
+++ b/A00_Common/spreadsheet/spreadsheet_fill.ts
@@ -7,22 +7,7 @@
 
 import type { Cell, CellRange, FillDirection, Workbook } from "./spreadsheet_types";
 import { moveFormula } from "./spreadsheet_refshift";
-
-/** 0 → `A` · 27 → `AB`(엔진 A 의 `spreadsheet_address.ts` 와 같은 규칙 · 채우기는 자기 것을 씀) */
-function colLetters(c: number): string {
-  let n = c + 1;
-  let s = "";
-  while (n > 0) {
-    const rem = (n - 1) % 26;
-    s = String.fromCharCode(65 + rem) + s;
-    n = Math.floor((n - 1) / 26);
-  }
-  return s;
-}
-
-function a1(r: number, c: number): string {
-  return `${colLetters(c)}${r + 1}`;
-}
+import { toA1 } from "./spreadsheet_address";
 
 function detectDirection(source: CellRange, target: CellRange): FillDirection {
   if (target.r1 > source.r1 && target.c0 === source.c0 && target.c1 === source.c1) return "down";
@@ -64,7 +49,7 @@ export function fillCells(
     const targetEnd = vertical ? target.r1 : target.c1;
     const lineLen = sourceEnd - sourceStart + 1;
 
-    const key = (pos: number): string => (vertical ? a1(pos, fixed) : a1(fixed, pos));
+    const key = (pos: number): string => (vertical ? toA1(pos, fixed) : toA1(fixed, pos));
     const sourceCells: (Cell | undefined)[] = [];
     for (let p = sourceStart; p <= sourceEnd; p++) sourceCells.push(sheetObj.칸[key(p)]);
 
diff --git a/A00_Common/spreadsheet/spreadsheet_grid.css b/A00_Common/spreadsheet/spreadsheet_grid.css
index 6ec0e9dd..024233ba 100644
--- a/A00_Common/spreadsheet/spreadsheet_grid.css
+++ b/A00_Common/spreadsheet/spreadsheet_grid.css
@@ -172,6 +172,19 @@
   z-index: 1;
 }
 
+/* 메모 칸 — 엑셀처럼 오른 위 모서리 빨간 세모. */
+.aislo-cell.has-comment::after {
+  content: "";
+  position: absolute;
+  top: 0;
+  right: 0;
+  width: 0;
+  height: 0;
+  border-style: solid;
+  border-width: 0 6px 6px 0;
+  border-color: transparent #c00 transparent transparent;
+}
+
 .aislo-grid__ref-highlight {
   position: absolute;
   box-sizing: border-box;
diff --git a/A00_Common/spreadsheet/spreadsheet_grid.ts b/A00_Common/spreadsheet/spreadsheet_grid.ts
index de32e299..2a7d5fbd 100644
--- a/A00_Common/spreadsheet/spreadsheet_grid.ts
+++ b/A00_Common/spreadsheet/spreadsheet_grid.ts
@@ -130,6 +130,7 @@ interface CellDisplay {
   hAlign: HAlign;
   title: string;
   isError: boolean;
+  color?: string;
 }
 
 function cellDisplay(
@@ -151,7 +152,7 @@ function cellDisplay(
   const isError = typeof scalar === "object" && scalar !== null && "error" in scalar;
   const hAlign: HAlign = hAlign0 !== "general" ? hAlign0 : formatted.정렬;
   const title = isError ? ((scalar as ErrorValue).why ?? formatted.글) : "";
-  return { text: formatted.글, hAlign, title, isError };
+  return { text: formatted.글, hAlign, title, isError, color: formatted.색 };
 }
 
 export function createGrid(ctx: SpreadsheetContext): GridHandle {
@@ -214,6 +215,7 @@ export function createGrid(ctx: SpreadsheetContext): GridHandle {
   let frozenCols = 0;
   let frozenW = 0;
   let frozenH = 0;
+  let lastSheetId = "";
 
   const resize = new ResizeObserver(() => layoutPanes());
   resize.observe(root);
@@ -313,6 +315,8 @@ export function createGrid(ctx: SpreadsheetContext): GridHandle {
         cellEl.style.height = `${h}px`;
         cellEl.dataset.r = String(r0);
         cellEl.dataset.c = String(c0);
+        const addr = toA1(r0, c0);
+        cellEl.dataset.addr = addr;
         const style = cellStyleAt(book, sheet, r0, c0);
         const borders: ResolvedBorders = resolveBoxBorders(
           book,
@@ -326,8 +330,11 @@ export function createGrid(ctx: SpreadsheetContext): GridHandle {
         );
         const display = cellDisplay(ctx, sheet, r0, c0, style.가로 ?? "general", style.형식);
         applyCellStyle(cellEl, style, borders, display.hAlign);
-        setCellText(cellEl, display.text, display.title || undefined);
+        if (display.color) cellEl.style.color = display.color;
+        const comment = sheet.comments?.[addr];
+        setCellText(cellEl, display.text, display.title || comment || undefined);
         cellEl.classList.toggle("is-error", display.isError);
+        cellEl.classList.toggle("has-comment", !!comment);
         cellEl.classList.toggle(
           "is-selected",
           ctx.selection.활성.r === r0 && ctx.selection.활성.c === c0,
@@ -478,6 +485,8 @@ export function createGrid(ctx: SpreadsheetContext): GridHandle {
 
   function render(): void {
     const sheet = ctx.sheet();
+    root.style.fontFamily = ctx.book.기본?.글꼴 ?? "";
+    root.style.fontSize = ctx.book.기본?.크기 ? `${ctx.book.기본.크기}pt` : "";
     colGeo = buildColGeometry(ctx.book, sheet);
     rowGeo = buildRowGeometry(ctx.book, sheet);
     extent = computeExtent(sheet);
@@ -486,8 +495,11 @@ export function createGrid(ctx: SpreadsheetContext): GridHandle {
     frozenCols = Math.min(sheet.틀고정?.열 ?? 0, extent.cols);
     spacer.style.width = "1px";
     spacer.style.height = "1px";
-    paneBR.scrollLeft = 0;
-    paneBR.scrollTop = 0;
+    if (sheet.id !== lastSheetId) {
+      lastSheetId = sheet.id;
+      paneBR.scrollLeft = 0;
+      paneBR.scrollTop = 0;
+    }
     layoutPanes();
   }
 
@@ -667,8 +679,17 @@ export function createGrid(ctx: SpreadsheetContext): GridHandle {
     };
   }
 
+  /** 칸이 든 판(틀고정 4 판 중 하나)의 안쪽 층 — 어느 판인지는 이 반환 요소로 앎. */
+  function paneLayerOf(r: number, c: number): HTMLElement {
+    const inFrozenRow = r < frozenRows;
+    const inFrozenCol = c < frozenCols;
+    if (inFrozenRow) return inFrozenCol ? paneTLInner : paneTRInner;
+    return inFrozenCol ? paneBLInner : paneBRInner;
+  }
+
+  /** 편집기 자리 — `layer` = 칸이 든 판의 안쪽 층 · `box` = 격자 뿌리 기준 화면 좌표(D 가 층 차이를 빼서 맞춤). */
   function editorSlot(r: number, c: number): { layer: HTMLElement; box: CellBox } {
-    return { layer: overlay, box: screenBoxOf(r, c) };
+    return { layer: paneLayerOf(r, c), box: screenBoxOf(r, c) };
   }
 
   function destroy(): void {
diff --git a/A00_Common/spreadsheet/spreadsheet_headers.ts b/A00_Common/spreadsheet/spreadsheet_headers.ts
index ac634b4f..3d8be157 100644
--- a/A00_Common/spreadsheet/spreadsheet_headers.ts
+++ b/A00_Common/spreadsheet/spreadsheet_headers.ts
@@ -100,7 +100,7 @@ class SparseGeometry implements LineGeometry {
 }
 
 export function buildColGeometry(book: Workbook, sheet: Sheet): LineGeometry {
-  const base = colCharsToPx(book.기본?.열폭 ?? DEFAULT_COL_CHARS);
+  const base = colCharsToPx(sheet.기본?.열폭 ?? book.기본?.열폭 ?? DEFAULT_COL_CHARS);
   const overrides = new Map<number, number>();
   for (const [key, info] of Object.entries(sheet.열 ?? {})) {
     const c = colIndex(key);
@@ -112,7 +112,7 @@ export function buildColGeometry(book: Workbook, sheet: Sheet): LineGeometry {
 }
 
 export function buildRowGeometry(book: Workbook, sheet: Sheet): LineGeometry {
-  const base = ptToPx(book.기본?.행높이 ?? DEFAULT_ROW_PT);
+  const base = ptToPx(sheet.기본?.행높이 ?? book.기본?.행높이 ?? DEFAULT_ROW_PT);
   const overrides = new Map<number, number>();
   for (const [key, info] of Object.entries(sheet.행 ?? {}) as [string, RowInfo][]) {
     const r = Number(key) - 1;
diff --git a/A00_Common/spreadsheet/spreadsheet_numfmt.ts b/A00_Common/spreadsheet/spreadsheet_numfmt.ts
index adde4c58..1351fcab 100644
--- a/A00_Common/spreadsheet/spreadsheet_numfmt.ts
+++ b/A00_Common/spreadsheet/spreadsheet_numfmt.ts
@@ -64,7 +64,12 @@ function extractColor(section: string): { rest: string; color?: string } {
   let color: string | undefined;
   const rest = section.replace(/\[([^\]]+)\]/g, (_m, inner: string) => {
     const lower = inner.toLowerCase();
-    if (COLOR_NAMES.includes(lower)) color = lower;
+    if (COLOR_NAMES.includes(lower)) {
+      color = lower;
+      return "";
+    }
+    const currency = /^\$([^-\]]*)(-[0-9A-Fa-f]+)?$/.exec(inner);
+    if (currency) return currency[1]; // `[$₩-412]` 등 통화 태그 → 글자만 남김
     return ""; // 조건 태그(`[>100]` 등)는 1단계에서 무시
   });
   return { rest, color };
@@ -78,6 +83,7 @@ type Tok =
   | { k: "point" }
   | { k: "percent" }
   | { k: "text" }
+  | { k: "general" }
   | { k: "lit"; ch: string };
 
 function tokenize(s: string): { toks: Tok[]; fillChar?: string } {
@@ -85,6 +91,12 @@ function tokenize(s: string): { toks: Tok[]; fillChar?: string } {
   let fillChar: string | undefined;
   for (let i = 0; i < s.length; i++) {
     const ch = s[i];
+    // 코드 속에 섞인 맨 `General`(따옴표 없이) — 실무 흔한 `General"개"` 같은 단위 접미 버릇.
+    if (s.slice(i, i + 7).toLowerCase() === "general") {
+      toks.push({ k: "general" });
+      i += 6;
+      continue;
+    }
     if (ch === '"') {
       let j = i + 1;
       while (j < s.length && s[j] !== '"') {
@@ -214,6 +226,10 @@ function renderNumericSection(toks: Tok[], magnitude: Frac): string {
       continue;
     }
     if (t.k === "text") continue; // 수 구역엔 의미 없음(방어)
+    if (t.k === "general") {
+      out += generalFormat(magnitude);
+      continue;
+    }
     out += t.ch;
   }
   return out;
@@ -238,34 +254,34 @@ function chooseSection(sections: string[], value: Frac): { code: string; forceMi
 }
 
 function formatNumber(value: Frac, code: string | undefined): FormattedText {
-  const trimmed = code?.trim();
-  if (!trimmed || trimmed.toLowerCase() === "general") {
+  if (code === undefined || code === "" || code.trim().toLowerCase() === "general") {
     return { 글: generalFormat(value), 정렬: "right" };
   }
-  const sections = splitSections(trimmed);
+  const sections = splitSections(code);
   const { code: chosen, forceMinus } = chooseSection(sections, value);
   const { rest, color } = extractColor(chosen);
   const { toks, fillChar } = tokenize(rest);
   const extra: Partial<FormattedText> = {};
   if (color) extra.색 = color;
   if (fillChar) extra.채움글 = fillChar;
-  if (!toks.some((t) => t.k === "digit")) {
+  const magnitude = cmp(value, ZERO) < 0 ? frac(-value.n, value.d) : value;
+  if (!toks.some((t) => t.k === "digit" || t.k === "general")) {
     let out = "";
     for (const t of toks) if (t.k === "lit") out += t.ch;
     return { 글: out, 정렬: "right", ...extra };
   }
-  const magnitude = cmp(value, ZERO) < 0 ? frac(-value.n, value.d) : value;
   const body = renderNumericSection(toks, magnitude);
   return { 글: (forceMinus ? "-" : "") + body, 정렬: "right", ...extra };
 }
 
 function formatText(value: string, code: string | undefined): FormattedText {
-  const trimmed = code?.trim();
-  if (!trimmed) return { 글: value, 정렬: "left" };
-  const sections = splitSections(trimmed);
-  // 구역 하나뿐(`;` 없음) = 그 구역이 수 · 글 모두에 적용(`General` 과 같은 이치) · 2~3 구역엔 글 자리가 없어 그대로.
-  const textCode =
-    sections.length >= 4 ? sections[3] : sections.length === 1 ? sections[0] : undefined;
+  if (code === undefined || code === "") return { 글: value, 정렬: "left" };
+  const sections = splitSections(code);
+  // 구역 하나뿐(`;` 없음)에 `@` 가 있을 때만 그 구역을 씀(순수 수 형식 하나뿐이면 글엔 안 씀) ·
+  // 넷째 구역은 명시적 글 자리라 `@` 없어도 그대로(고정 라벨 버릇) · 2~3 구역엔 글 자리가 없어 그대로.
+  let textCode: string | undefined;
+  if (sections.length >= 4) textCode = sections[3];
+  else if (sections.length === 1 && sections[0].includes("@")) textCode = sections[0];
   if (textCode === undefined) return { 글: value, 정렬: "left" };
   const { rest, color } = extractColor(textCode);
   const { toks, fillChar } = tokenize(rest);
diff --git a/M02_MasterTemplete/M02_MasterTemplete_Spreadsheet_Trial.ts b/M02_MasterTemplete/M02_MasterTemplete_Spreadsheet_Trial.ts
index 7d655959..bbe3ffc2 100644
--- a/M02_MasterTemplete/M02_MasterTemplete_Spreadsheet_Trial.ts
+++ b/M02_MasterTemplete/M02_MasterTemplete_Spreadsheet_Trial.ts
@@ -56,7 +56,10 @@ export function mountSpreadsheetTrial(
         readSpreadsheetTrial(),
       ]);
       if (!alive) return;
-      sheet = createSpreadsheet(area, got.문서 as Workbook, { onChange: () => onDirty(true) });
+      sheet = createSpreadsheet(area, got.문서 as Workbook, {
+        onChange: () => onDirty(true),
+        inspect: true, // ⚠ 임시 — 브레인 검증용 문맥(window.__aisloSheet) · 산출근거 카드는 안 넘김
+      });
     } catch (error) {
       if (!alive) return;
       area.replaceChildren(el("p", { className: "m02-trial__empty", text: why(error) }));
diff --git a/M02_MasterTemplete/M02_MasterTemplete_Store.py b/M02_MasterTemplete/M02_MasterTemplete_Store.py
index 7879945c..670d664a 100644
--- a/M02_MasterTemplete/M02_MasterTemplete_Store.py
+++ b/M02_MasterTemplete/M02_MasterTemplete_Store.py
@@ -32,6 +32,10 @@ _BASIS_HEAD_STYLE = {
 }
 _NUMBER = re.compile(r"^구-(\d+)$")
 _BAD_NAME = re.compile(r'[\\/:*?"<>|\x00-\x1f]|\.\.')
+# 도각 없는 빈 CAD 문서의 기본 도면층 — 없으면 B07 CAD 가 못 엶("Cannot read properties
+# of undefined (reading 'length')") · CAD 쪽도 없으면 새로 채우지만(2026-09-27 sub1 고침)
+# 뿌리도 처음부터 채움
+_BLANK_LAYER = {"id": "기본", "name": "기본", "isVisible": True, "isLocked": False}
 # ponytail: 저장은 한 번에 하나(프로세스 안 잠금) · 서버를 여럿 띄우면 파일 잠금으로
 _LOCK = threading.Lock()
 
@@ -158,7 +162,7 @@ def create_structure(column: str) -> dict[str, Any]:
             "판": 1,
             "열": column,
             "도번": f"구-{number:02d}",
-            "도면": {"format": 6, "entities": []},
+            "도면": {"format": 6, "entities": [], "layers": [dict(_BLANK_LAYER)]},
         }
         atomic_write_json(path, doc)
     ensure_basis(column)
diff --git a/M02_MasterTemplete/M02_MasterTemplete_UI_Side.ts b/M02_MasterTemplete/M02_MasterTemplete_UI_Side.ts
index 86334a25..97e462cc 100644
--- a/M02_MasterTemplete/M02_MasterTemplete_UI_Side.ts
+++ b/M02_MasterTemplete/M02_MasterTemplete_UI_Side.ts
@@ -45,7 +45,13 @@ function stubDoc(kind: Kind, name: string): unknown {
         합계줄: [],
         보기: {},
       }
-    : { format: 6, entities: [] };
+    : {
+        format: 6,
+        entities: [],
+        // 기본 도면층 하나 — 없으면 B07 CAD 가 못 엶("Cannot read properties of
+        // undefined (reading 'length')", 2026-09-27 실측)
+        layers: [{ id: "기본", name: "기본", isVisible: true, isLocked: false }],
+      };
 }
 
 export interface SideOptions {
diff --git a/resources/master_template/structure/be.json b/resources/master_template/structure/be.json
index aeee77e4..816e6161 100644
--- a/resources/master_template/structure/be.json
+++ b/resources/master_template/structure/be.json
@@ -6,6 +6,14 @@
   "도번": "구-25",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/bg.json b/resources/master_template/structure/bg.json
index 30aa8bf5..38da2c65 100644
--- a/resources/master_template/structure/bg.json
+++ b/resources/master_template/structure/bg.json
@@ -6,6 +6,14 @@
   "도번": "구-33",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/bm_area.json b/resources/master_template/structure/bm_area.json
index 9337dc2f..e967ce94 100644
--- a/resources/master_template/structure/bm_area.json
+++ b/resources/master_template/structure/bm_area.json
@@ -6,6 +6,14 @@
   "도번": "구-23",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/bm_len.json b/resources/master_template/structure/bm_len.json
index 88ef0ab3..2d58b811 100644
--- a/resources/master_template/structure/bm_len.json
+++ b/resources/master_template/structure/bm_len.json
@@ -6,6 +6,14 @@
   "도번": "구-22",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/bx_len.json b/resources/master_template/structure/bx_len.json
index e4cb34ae..404132e7 100644
--- a/resources/master_template/structure/bx_len.json
+++ b/resources/master_template/structure/bx_len.json
@@ -6,6 +6,14 @@
   "도번": "구-12",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/bx_wing.json b/resources/master_template/structure/bx_wing.json
index fb99203f..989810ec 100644
--- a/resources/master_template/structure/bx_wing.json
+++ b/resources/master_template/structure/bx_wing.json
@@ -6,6 +6,14 @@
   "도번": "구-13",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/cs.json b/resources/master_template/structure/cs.json
index dd24845b..e94a7221 100644
--- a/resources/master_template/structure/cs.json
+++ b/resources/master_template/structure/cs.json
@@ -6,6 +6,14 @@
   "도번": "구-35",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/ec.json b/resources/master_template/structure/ec.json
index e119aa89..6e5fc283 100644
--- a/resources/master_template/structure/ec.json
+++ b/resources/master_template/structure/ec.json
@@ -6,6 +6,14 @@
   "도번": "구-24",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/etc.json b/resources/master_template/structure/etc.json
index c9c9af6f..aa34ef10 100644
--- a/resources/master_template/structure/etc.json
+++ b/resources/master_template/structure/etc.json
@@ -6,6 +6,14 @@
   "도번": "구-36",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/fb.json b/resources/master_template/structure/fb.json
index 5c7d0911..50a7f179 100644
--- a/resources/master_template/structure/fb.json
+++ b/resources/master_template/structure/fb.json
@@ -6,6 +6,14 @@
   "도번": "구-14",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/fp_l.json b/resources/master_template/structure/fp_l.json
index 69bb0bc6..216d0344 100644
--- a/resources/master_template/structure/fp_l.json
+++ b/resources/master_template/structure/fp_l.json
@@ -6,6 +6,14 @@
   "도번": "구-16",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/fp_w.json b/resources/master_template/structure/fp_w.json
index 89831d37..6b4ea5fa 100644
--- a/resources/master_template/structure/fp_w.json
+++ b/resources/master_template/structure/fp_w.json
@@ -6,6 +6,14 @@
   "도번": "구-15",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/gr_curb.json b/resources/master_template/structure/gr_curb.json
index 0d631708..a2a55ce9 100644
--- a/resources/master_template/structure/gr_curb.json
+++ b/resources/master_template/structure/gr_curb.json
@@ -6,6 +6,14 @@
   "도번": "구-30",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/gr_rail.json b/resources/master_template/structure/gr_rail.json
index 8c93aedc..f11eca4a 100644
--- a/resources/master_template/structure/gr_rail.json
+++ b/resources/master_template/structure/gr_rail.json
@@ -6,6 +6,14 @@
   "도번": "구-29",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/gr_sign.json b/resources/master_template/structure/gr_sign.json
index c3afa1f7..1992f3fe 100644
--- a/resources/master_template/structure/gr_sign.json
+++ b/resources/master_template/structure/gr_sign.json
@@ -6,6 +6,14 @@
   "도번": "구-31",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/h_break.json b/resources/master_template/structure/h_break.json
index c78994c2..e286404f 100644
--- a/resources/master_template/structure/h_break.json
+++ b/resources/master_template/structure/h_break.json
@@ -6,6 +6,14 @@
   "도번": "구-47",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/h_ford_basin.json b/resources/master_template/structure/h_ford_basin.json
index 5c7f9ff7..04ae088b 100644
--- a/resources/master_template/structure/h_ford_basin.json
+++ b/resources/master_template/structure/h_ford_basin.json
@@ -6,6 +6,14 @@
   "도번": "구-45",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/h_intake.json b/resources/master_template/structure/h_intake.json
index 0986d7da..c6fe90db 100644
--- a/resources/master_template/structure/h_intake.json
+++ b/resources/master_template/structure/h_intake.json
@@ -6,6 +6,14 @@
   "도번": "구-37",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/h_pg_rail.json b/resources/master_template/structure/h_pg_rail.json
index ff3fc485..bff75d82 100644
--- a/resources/master_template/structure/h_pg_rail.json
+++ b/resources/master_template/structure/h_pg_rail.json
@@ -6,6 +6,14 @@
   "도번": "구-43",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/h_pv_rail.json b/resources/master_template/structure/h_pv_rail.json
index be30d771..07592528 100644
--- a/resources/master_template/structure/h_pv_rail.json
+++ b/resources/master_template/structure/h_pv_rail.json
@@ -6,6 +6,14 @@
   "도번": "구-42",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/h_rip_c.json b/resources/master_template/structure/h_rip_c.json
index b6bbd7b4..b119a7d6 100644
--- a/resources/master_template/structure/h_rip_c.json
+++ b/resources/master_template/structure/h_rip_c.json
@@ -6,6 +6,14 @@
   "도번": "구-38",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/h_rip_m.json b/resources/master_template/structure/h_rip_m.json
index d6913c8d..57fcb5a2 100644
--- a/resources/master_template/structure/h_rip_m.json
+++ b/resources/master_template/structure/h_rip_m.json
@@ -6,6 +6,14 @@
   "도번": "구-39",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/h_rockfall.json b/resources/master_template/structure/h_rockfall.json
index da684b1e..b6fa2417 100644
--- a/resources/master_template/structure/h_rockfall.json
+++ b/resources/master_template/structure/h_rockfall.json
@@ -6,6 +6,14 @@
   "도번": "구-46",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/h_soil_ditch.json b/resources/master_template/structure/h_soil_ditch.json
index a906ae5b..643bca97 100644
--- a/resources/master_template/structure/h_soil_ditch.json
+++ b/resources/master_template/structure/h_soil_ditch.json
@@ -6,6 +6,14 @@
   "도번": "구-44",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/h_stone_bed.json b/resources/master_template/structure/h_stone_bed.json
index bfb2b924..a1719680 100644
--- a/resources/master_template/structure/h_stone_bed.json
+++ b/resources/master_template/structure/h_stone_bed.json
@@ -6,6 +6,14 @@
   "도번": "구-41",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/h_stone_ch.json b/resources/master_template/structure/h_stone_ch.json
index 31e9ac8a..377d7206 100644
--- a/resources/master_template/structure/h_stone_ch.json
+++ b/resources/master_template/structure/h_stone_ch.json
@@ -6,6 +6,14 @@
   "도번": "구-40",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/h_waste.json b/resources/master_template/structure/h_waste.json
index ccfff700..c89e4075 100644
--- a/resources/master_template/structure/h_waste.json
+++ b/resources/master_template/structure/h_waste.json
@@ -6,6 +6,14 @@
   "도번": "구-48",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/memo.json b/resources/master_template/structure/memo.json
index 51ebf6c0..84f694ac 100644
--- a/resources/master_template/structure/memo.json
+++ b/resources/master_template/structure/memo.json
@@ -6,6 +6,14 @@
   "도번": "구-49",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/mr.json b/resources/master_template/structure/mr.json
index 482a06df..d260d2a5 100644
--- a/resources/master_template/structure/mr.json
+++ b/resources/master_template/structure/mr.json
@@ -6,6 +6,14 @@
   "도번": "구-32",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/ms.json b/resources/master_template/structure/ms.json
index 8b828a33..c91f50ef 100644
--- a/resources/master_template/structure/ms.json
+++ b/resources/master_template/structure/ms.json
@@ -6,6 +6,14 @@
   "도번": "구-20",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/no.json b/resources/master_template/structure/no.json
index ca136814..94d29720 100644
--- a/resources/master_template/structure/no.json
+++ b/resources/master_template/structure/no.json
@@ -6,6 +6,14 @@
   "도번": "구-01",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/od_cnt.json b/resources/master_template/structure/od_cnt.json
index 383d961a..ee4e3112 100644
--- a/resources/master_template/structure/od_cnt.json
+++ b/resources/master_template/structure/od_cnt.json
@@ -6,6 +6,14 @@
   "도번": "구-18",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/od_len.json b/resources/master_template/structure/od_len.json
index 29f1c329..4469b206 100644
--- a/resources/master_template/structure/od_len.json
+++ b/resources/master_template/structure/od_len.json
@@ -6,6 +6,14 @@
   "도번": "구-17",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/pg_in.json b/resources/master_template/structure/pg_in.json
index 7b5733fa..86bf15e2 100644
--- a/resources/master_template/structure/pg_in.json
+++ b/resources/master_template/structure/pg_in.json
@@ -6,6 +6,14 @@
   "도번": "구-11",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/pp_cp.json b/resources/master_template/structure/pp_cp.json
index 73186323..3d19815b 100644
--- a/resources/master_template/structure/pp_cp.json
+++ b/resources/master_template/structure/pp_cp.json
@@ -6,6 +6,14 @@
   "도번": "구-10",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/pp_len.json b/resources/master_template/structure/pp_len.json
index eadad960..ea38b17c 100644
--- a/resources/master_template/structure/pp_len.json
+++ b/resources/master_template/structure/pp_len.json
@@ -6,6 +6,14 @@
   "도번": "구-09",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/ps.json b/resources/master_template/structure/ps.json
index 8ba9010c..e867c8e1 100644
--- a/resources/master_template/structure/ps.json
+++ b/resources/master_template/structure/ps.json
@@ -6,6 +6,14 @@
   "도번": "구-34",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/pv_a.json b/resources/master_template/structure/pv_a.json
index 30a22f89..0412d82f 100644
--- a/resources/master_template/structure/pv_a.json
+++ b/resources/master_template/structure/pv_a.json
@@ -6,6 +6,14 @@
   "도번": "구-07",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/pv_b.json b/resources/master_template/structure/pv_b.json
index ba01319e..426eb421 100644
--- a/resources/master_template/structure/pv_b.json
+++ b/resources/master_template/structure/pv_b.json
@@ -6,6 +6,14 @@
   "도번": "구-04",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/pv_jt.json b/resources/master_template/structure/pv_jt.json
index a0c6b376..3f488892 100644
--- a/resources/master_template/structure/pv_jt.json
+++ b/resources/master_template/structure/pv_jt.json
@@ -6,6 +6,14 @@
   "도번": "구-08",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/pv_l.json b/resources/master_template/structure/pv_l.json
index 363b41ec..8a9954e2 100644
--- a/resources/master_template/structure/pv_l.json
+++ b/resources/master_template/structure/pv_l.json
@@ -6,6 +6,14 @@
   "도번": "구-05",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/pv_w.json b/resources/master_template/structure/pv_w.json
index 73dcb13b..022c985f 100644
--- a/resources/master_template/structure/pv_w.json
+++ b/resources/master_template/structure/pv_w.json
@@ -6,6 +6,14 @@
   "도번": "구-06",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/rf.json b/resources/master_template/structure/rf.json
index 580123df..c54858b3 100644
--- a/resources/master_template/structure/rf.json
+++ b/resources/master_template/structure/rf.json
@@ -6,6 +6,14 @@
   "도번": "구-26",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/rv.json b/resources/master_template/structure/rv.json
index 01aa92db..6b51501d 100644
--- a/resources/master_template/structure/rv.json
+++ b/resources/master_template/structure/rv.json
@@ -6,6 +6,14 @@
   "도번": "구-03",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/rw.json b/resources/master_template/structure/rw.json
index 085121ea..20b14af2 100644
--- a/resources/master_template/structure/rw.json
+++ b/resources/master_template/structure/rw.json
@@ -6,6 +6,14 @@
   "도번": "구-19",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/sg.json b/resources/master_template/structure/sg.json
index 450dd30f..1cfb3d61 100644
--- a/resources/master_template/structure/sg.json
+++ b/resources/master_template/structure/sg.json
@@ -6,6 +6,14 @@
   "도번": "구-21",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/sta.json b/resources/master_template/structure/sta.json
index da54464c..7d0ebe77 100644
--- a/resources/master_template/structure/sta.json
+++ b/resources/master_template/structure/sta.json
@@ -6,6 +6,14 @@
   "도번": "구-02",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/ta.json b/resources/master_template/structure/ta.json
index 64201388..ab34875a 100644
--- a/resources/master_template/structure/ta.json
+++ b/resources/master_template/structure/ta.json
@@ -6,6 +6,14 @@
   "도번": "구-28",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/master_template/structure/wy.json b/resources/master_template/structure/wy.json
index 5eebbb98..39b4028a 100644
--- a/resources/master_template/structure/wy.json
+++ b/resources/master_template/structure/wy.json
@@ -6,6 +6,14 @@
   "도번": "구-27",
   "도면": {
     "format": 6,
-    "entities": []
+    "entities": [],
+    "layers": [
+      {
+        "id": "기본",
+        "name": "기본",
+        "isVisible": true,
+        "isLocked": false
+      }
+    ]
   }
 }
diff --git a/resources/tester/spreadsheet/spreadsheet_b_test_entry.ts b/resources/tester/spreadsheet/spreadsheet_b_test_entry.ts
index 7f78fccb..92972b24 100644
--- a/resources/tester/spreadsheet/spreadsheet_b_test_entry.ts
+++ b/resources/tester/spreadsheet/spreadsheet_b_test_entry.ts
@@ -216,6 +216,34 @@ ok("0.00", fmt(frac(BigInt(150), 100n), "0.00") === "1.50", fmt(frac(150n, 100n)
 ok("#,##0", fmt(frac(1234567n), "#,##0") === "1,234,567", fmt(frac(1234567n), "#,##0"));
 ok("천 나눔 끝쉼표", fmt(frac(1234000n), "#,##0,") === "1,234", fmt(frac(1234000n), "#,##0,"));
 ok("퍼센트", fmt(frac(50n, 100n), "0%") === "50%", fmt(frac(50n, 100n), "0%"));
+
+// 실무 구조도 xlsx 세 벌 실측 코드(2026-09-27 대조) — 회귀 방지.
+ok(
+  "_x 폭띄움 끝쉼표",
+  fmt(frac(3n), "0.00_ ") === "3.00 ",
+  JSON.stringify(fmt(frac(3n), "0.00_ ")),
+);
+ok(
+  "_x 글에는 안 먹음(순수 수 형식)",
+  fmt("외부벽체", "0.00_ ") === "외부벽체",
+  fmt("외부벽체", "0.00_ "),
+);
+ok(
+  "General 단위접미(실무 버릇)",
+  fmt(frac(4n), 'General"열"') === "4열",
+  fmt(frac(4n), 'General"열"'),
+);
+ok(
+  "회계형(끝 구역 글)",
+  fmt(frac(1044n, 1000n), '_-* #,##0.00_-;\\-* #,##0.00_-;_-* "-"_-;_-@_-') === " 1.04 ",
+  fmt(frac(1044n, 1000n), '_-* #,##0.00_-;\\-* #,##0.00_-;_-* "-"_-;_-@_-'),
+);
+ok(
+  "통화 태그([$기호-로캘])",
+  fmt(frac(2n), '_-[$€-2]* #,##0.00_-;-[$€-2]* #,##0.00_-;_-[$€-2]* "-"??_-') === " €2.00 ",
+  fmt(frac(2n), '_-[$€-2]* #,##0.00_-;-[$€-2]* #,##0.00_-;_-[$€-2]* "-"??_-'),
+);
+ok("따옴표 접두·접미", fmt(frac(800n), '"φ"###') === "φ800", fmt(frac(800n), '"φ"###'));
 ok(
   "음수 회계형",
   fmt(frac(-150n, 100n), "0.00_);[Red](0.00)") === "(1.50)",
@@ -278,6 +306,15 @@ function bookWith(cells: Record<string, Cell>): Workbook {
     JSON.stringify(out),
   );
 }
+{
+  const book = bookWith({ B1: { 식: "A1*2" } });
+  const out = fillCells(book, "s1", { r0: 0, c0: 1, r1: 0, c1: 1 }, { r0: 0, c0: 1, r1: 2, c1: 1 });
+  ok(
+    "채우기 식 상대 이동(A moveFormula)",
+    out.B2?.식 === "A2*2" && out.B3?.식 === "A3*2",
+    JSON.stringify(out),
+  );
+}
 
 // ── 요약 ────────────────────────────────────────────────────────────────
 
diff --git a/resources/tester/spreadsheet/spreadsheet_grid_test.html b/resources/tester/spreadsheet/spreadsheet_grid_test.html
new file mode 100644
index 00000000..f393d1d4
--- /dev/null
+++ b/resources/tester/spreadsheet/spreadsheet_grid_test.html
@@ -0,0 +1,22 @@
+<!doctype html>
+<html lang="ko">
+  <head>
+    <meta charset="UTF-8" />
+    <title>C 격자 시험 틀</title>
+    <style>
+      html,
+      body {
+        margin: 0;
+        height: 100%;
+      }
+      #app {
+        position: fixed;
+        inset: 0;
+      }
+    </style>
+  </head>
+  <body>
+    <div id="app"></div>
+    <script type="module" src="./spreadsheet_grid_test.ts"></script>
+  </body>
+</html>
diff --git a/resources/tester/spreadsheet/spreadsheet_grid_test.ts b/resources/tester/spreadsheet/spreadsheet_grid_test.ts
new file mode 100644
index 00000000..ed13e30c
--- /dev/null
+++ b/resources/tester/spreadsheet/spreadsheet_grid_test.ts
@@ -0,0 +1,161 @@
+/* =============================================================================
+ * spreadsheet_grid_test.ts
+ * C(격자) 화면 시험 틀 — 병합 · 틀고정 · 숨김 · 폭 · hair 선 · 균등 분할 · 선택 영역 가운데 ·
+ * [Red] 음수 서식 · 1만 행 스크롤 때 DOM 칸 수를 ORCA 로 확인. D · 엔진이 없으니 이 파일이
+ * `SpreadsheetContext` 를 최소로 흉내 낸다(엔진 값은 안 씀 — 식 칸이 없음).
+ * ========================================================================== */
+
+import { createGrid } from "../../../A00_Common/spreadsheet/spreadsheet_grid";
+import type {
+  CalcEngine,
+  Command,
+  History,
+  Sheet,
+  Workbook,
+} from "../../../A00_Common/spreadsheet/spreadsheet_types";
+import { colIndex } from "../../../A00_Common/spreadsheet/spreadsheet_address";
+import type {
+  GridHandle,
+  SpreadsheetContext,
+} from "../../../A00_Common/spreadsheet/spreadsheet_view_types";
+
+const sheet: Sheet = {
+  id: "s1",
+  이름: "시험",
+  칸: {
+    A1: { 값: "□격자 시험 — 병합 · 틀고정 · 숨김 · hair 선", 서식: 1 },
+    A3: { 값: "공종", 서식: 2 },
+    B3: { 값: "규격", 서식: 2 },
+    C3: { 값: "산출 내역", 서식: 2 },
+    G3: { 값: "단위", 서식: 2 },
+    H3: { 값: "수량", 서식: 2 },
+    A4: { 값: "터파기", 서식: 3 },
+    C4: { 값: "균등 분할 정렬 보기 글", 서식: 4 },
+    H4: { 값: -12.5, 서식: 6 },
+    A6: { 값: "선택 영역 가운데(centerContinuous) 보기", 서식: 5 },
+    A8: { 값: "hair 테두리 칸", 서식: 3 },
+    B8: { 값: 3.14159, 서식: 7 },
+    J10000: { 값: "맨 끝 칸(1만 행 스크롤 확인용)" },
+  },
+  comments: { H4: "메모 — ROUNDDOWN 끝수 확인" },
+  병합: ["A1:H1", "B8:C9"],
+  열: { A: { 폭: 14 }, D: { 숨김: true } },
+  행: { "1": { 높이: 22 }, "5": { 숨김: true } },
+  틀고정: { 행: 3, 열: 1 },
+  보기: { 눈금선: true },
+};
+
+const book: Workbook = {
+  종류: "통합문서",
+  판: 1,
+  열: "test",
+  기본: { 글꼴: "굴림", 크기: 10, 열폭: 8.43, 행높이: 15 },
+  서식: [
+    {},
+    { 크기: 14, 굵게: true },
+    {
+      가로: "center",
+      세로: "center",
+      채움: "#F2F2F2",
+      테두리: {
+        위: { 선: "thin" },
+        아래: { 선: "thin" },
+        왼: { 선: "thin" },
+        오른: { 선: "thin" },
+      },
+    },
+    { 세로: "center", 테두리: { 위: { 선: "hair" }, 아래: { 선: "hair" } } },
+    { 가로: "distributed", 세로: "center" },
+    { 가로: "centerContinuous", 세로: "center" },
+    { 형식: "0.00;[Red]-0.00" },
+    {
+      형식: "0.0000",
+      테두리: {
+        위: { 선: "hair" },
+        아래: { 선: "hair" },
+        왼: { 선: "hair" },
+        오른: { 선: "hair" },
+      },
+    },
+  ],
+  시트: [sheet],
+  활성: "s1",
+};
+
+function noopEngine(): CalcEngine {
+  return {
+    update: () => [],
+    rebuild: () => {},
+    value: () => null,
+    precedents: () => [],
+    snapshot: () => ({}),
+  };
+}
+
+function noopHistory(): History {
+  return {
+    push: () => {},
+    undo: () => null,
+    redo: () => null,
+    canUndo: () => false,
+    canRedo: () => false,
+    clear: () => {},
+  };
+}
+
+let grid!: GridHandle;
+
+const ctx: SpreadsheetContext = {
+  root: document.getElementById("app")!,
+  book,
+  readOnly: false,
+  engine: noopEngine(),
+  history: noopHistory(),
+  selection: {
+    시트: "s1",
+    범위: [{ r0: 2, c0: 2, r1: 2, c1: 2 }],
+    활성: { r: 2, c: 2 },
+    기준: { r: 2, c: 2 },
+  },
+  sheet: () => sheet,
+  dispatch: (command: Command) => {
+    if (command.종류 === "열폭") {
+      const c0 = command.열[0];
+      const key = c0 >= 0 ? String.fromCharCode(65 + c0) : "A"; // 시험 데이터가 A~J 안쪽이라 단순 변환으로 충분
+      sheet.열 = { ...sheet.열, [key]: { ...sheet.열?.[key], 폭: command.폭 ?? undefined } };
+    } else if (command.종류 === "행높이") {
+      const r0 = command.행[0];
+      sheet.행 = {
+        ...sheet.행,
+        [String(r0 + 1)]: { ...sheet.행?.[String(r0 + 1)], 높이: command.높이 ?? undefined },
+      };
+    }
+    grid.render();
+  },
+  undo: () => {},
+  redo: () => {},
+  select: () => grid.renderSelection(),
+  showSheet: () => {},
+  get grid() {
+    return grid;
+  },
+  editor: {
+    editing: () => false,
+    begin: () => {},
+    commit: () => {},
+    cancel: () => {},
+    sync: () => {},
+  },
+} as SpreadsheetContext;
+
+grid = createGrid(ctx);
+ctx.root.append(grid.root);
+
+// ORCA 수치 확인용 — 눈에 안 보이는 전역에 걸어 둠(콘솔 · eval 로 셈).
+(window as unknown as { __gridTest: unknown }).__gridTest = {
+  grid,
+  sheet,
+  book,
+  colIndex,
+  countCells: () => grid.root.querySelectorAll(".aislo-cell").length,
+};
diff --git a/resources/tester/spreadsheet/spreadsheet_numfmt_survey_entry.ts b/resources/tester/spreadsheet/spreadsheet_numfmt_survey_entry.ts
new file mode 100644
index 00000000..3ade8659
--- /dev/null
+++ b/resources/tester/spreadsheet/spreadsheet_numfmt_survey_entry.ts
@@ -0,0 +1,43 @@
+/* =============================================================================
+ * spreadsheet_numfmt_survey_entry.ts  (B 자기 시험)
+ * 실무 구조도 xlsx 세 벌에서 뽑은 실제 숫자 형식 코드 전부를 numfmt 로 돌려 사람이 대조.
+ * 입력 = 시험이 openpyxl 로 미리 뽑은 JSON(코드 · 실측 수 · 실측 글 견본).
+ * ========================================================================== */
+
+import { readFileSync } from "node:fs";
+import { toFrac } from "@ui/sheet/ui_template_sheet_frac";
+import { formatValue } from "../../../A00_Common/spreadsheet/spreadsheet_numfmt";
+
+interface CodeSample {
+  code: string;
+  count: number;
+  num: number | null;
+  str: string | null;
+}
+
+const inputPath = process.argv[2];
+const samples: CodeSample[] = JSON.parse(readFileSync(inputPath, "utf-8"));
+
+const rows = samples.map((s) => {
+  let numOut: string | null = null;
+  let numErr: string | null = null;
+  if (s.num !== null) {
+    try {
+      numOut = formatValue(toFrac(s.num), s.code).글;
+    } catch (e) {
+      numErr = String(e);
+    }
+  }
+  let strOut: string | null = null;
+  let strErr: string | null = null;
+  if (s.str !== null) {
+    try {
+      strOut = formatValue(s.str, s.code).글;
+    } catch (e) {
+      strErr = String(e);
+    }
+  }
+  return { ...s, numOut, numErr, strOut, strErr };
+});
+
+console.log(JSON.stringify(rows, null, 1));
diff --git a/resources/tester/spreadsheet/test_spreadsheet_size.py b/resources/tester/spreadsheet/test_spreadsheet_size.py
index 4b4d2580..5fad6bd2 100644
--- a/resources/tester/spreadsheet/test_spreadsheet_size.py
+++ b/resources/tester/spreadsheet/test_spreadsheet_size.py
@@ -60,7 +60,10 @@ def test_M02_만_늦게_불러옴():
         check=True,
     ).stdout.splitlines()
     for rel in listed:
-        if rel.startswith("A00_Common/spreadsheet/") or not (ROOT / rel).is_file():
+        # 시험용 진입(`resources/tester/`)은 앱 번들 밖
+        if rel.startswith(("A00_Common/spreadsheet/", "resources/tester/")):
+            continue
+        if not (ROOT / rel).is_file():
             continue
         text = (ROOT / rel).read_text(encoding="utf-8", errors="replace")
         if "spreadsheet/spreadsheet" not in text:
diff --git a/resources/tester/test_m02_structure.py b/resources/tester/test_m02_structure.py
index 9fda2eba..6817c259 100644
--- a/resources/tester/test_m02_structure.py
+++ b/resources/tester/test_m02_structure.py
@@ -35,8 +35,10 @@ def test_새로_도번_자동_409_없는_열(client):
         "pp_len",
         "구-01",
     )
-    # 도각 없는 전용 화면 — 그린 만큼이 설계 영역
-    assert doc["도면"] == {"format": 6, "entities": []}
+    # 도각 없는 전용 화면 — 그린 만큼이 설계 영역 · 기본 도면층 하나(없으면 CAD 가 못 엶)
+    assert doc["도면"]["format"] == 6
+    assert doc["도면"]["entities"] == []
+    assert len(doc["도면"]["layers"]) == 1
     # 산출근거는 구조물 문서 밖 — 같은 열 id 로 따로 한 통합문서
     assert "산출근거" not in doc
     assert client.get("/api/m02/templates/basis/pp_len").json()["문서"]["종류"] == "통합문서"
diff --git a/resources/tester/test_spreadsheet_numfmt_survey.py b/resources/tester/test_spreadsheet_numfmt_survey.py
new file mode 100644
index 00000000..62e33771
--- /dev/null
+++ b/resources/tester/test_spreadsheet_numfmt_survey.py
@@ -0,0 +1,105 @@
+"""numfmt — 실무 구조도 xlsx 세 벌 실측 숫자 형식 코드 전부를 돌려 안 죽는지 대조(2026-09-27).
+
+`resources/knowledge/original/실무문서/` 세 벌(openpyxl 로 읽기만 · 안 고침)에서 쓰인 서로 다른
+숫자 형식 코드를 모아 `spreadsheet_numfmt_survey_entry.ts`(vite ssr → node)로 돌린다.
+값별 정답은 실제 엑셀이 있어야 재는데(이 환경엔 없음) `resources/tester/spreadsheet/
+spreadsheet_b_test_entry.ts` 에 실측 코드 몇 개를 손으로 대조한 회귀 시험을 이미 넣었다 —
+여기는 "실무에 쓰인 코드 전부가 죽지 않고 뭔가 보이는 글을 냄"만 잰다(폭넓은 그물).
+
+알려진 빈 자리(1단계 밖 · `9_엑셀검토.md` 형식 부분집합에 없음):
+- 분수 형식(`0/0`, `# ?/?` 류) — 미지원 · 자리표시만 있고 값은 틀리게 나옴.
+"""
+
+from __future__ import annotations
+
+import json
+import shutil
+import subprocess
+import tempfile
+from pathlib import Path
+
+import openpyxl
+import pytest
+
+ROOT = Path(__file__).resolve().parents[2]
+ENTRY = ROOT / "resources" / "tester" / "spreadsheet" / "spreadsheet_numfmt_survey_entry.ts"
+VITE = ROOT / "config" / "node_modules" / "vite" / "bin" / "vite.js"
+
+FILES = [
+    ROOT
+    / "resources/knowledge/original/실무문서/25년 산불진화임도(기번8)(울진소광)/1. 설계원본/02-수량/07-구조도-소광리.xlsx",
+    ROOT
+    / "resources/knowledge/original/실무문서/2024년 간선임도(기번3-울진.대흥)(공통)/1. 설계원본/02 산출자료/5. 구조도(기번3).xlsx",
+    ROOT
+    / "resources/knowledge/original/실무문서/20250527 2025년 계류보전사업(기번1-영덕.병곡.영리.산214-1)(변경)/02.엑셀자료/구조도/구조도(변경).xlsx",
+]
+
+# 미지원으로 이미 아는 코드(1단계 밖 · 분수 형식) — 죽지 않아도 값이 틀리므로 미리 뺌.
+KNOWN_UNSUPPORTED = {"0/0"}
+
+pytestmark = pytest.mark.skipif(
+    not all(f.is_file() for f in FILES) or shutil.which("node") is None,
+    reason="실무 xlsx 세 벌 또는 node 가 없음",
+)
+
+
+def _collect_codes() -> list[dict]:
+    codes: dict[str, dict] = {}
+    for f in FILES:
+        wb = openpyxl.load_workbook(f, data_only=True, read_only=True)
+        for ws in wb.worksheets:
+            for row in ws.iter_rows():
+                for cell in row:
+                    if cell.value is None or isinstance(cell.value, bool):
+                        continue
+                    fmt = cell.number_format
+                    if fmt == "General":
+                        continue
+                    info = codes.setdefault(fmt, {"count": 0, "num": None, "str": None})
+                    info["count"] += 1
+                    if isinstance(cell.value, (int, float)) and info["num"] is None:
+                        info["num"] = cell.value
+                    if isinstance(cell.value, str) and info["str"] is None:
+                        info["str"] = cell.value
+        wb.close()
+    return [{"code": k, **v} for k, v in codes.items()]
+
+
+def _run_survey(samples: list[dict]) -> list[dict]:
+    with tempfile.TemporaryDirectory(prefix="numfmt_survey_") as outdir:
+        entry_rel = "../" + str(ENTRY.relative_to(ROOT)).replace("\\", "/")
+        build = subprocess.run(
+            ["node", str(VITE), "build", "--configLoader", "runner", "--ssr", entry_rel, "--outDir", outdir],
+            cwd=str(ROOT),
+            capture_output=True,
+            text=True,
+            encoding="utf-8",
+            errors="replace",
+            timeout=120,
+        )
+        assert build.returncode == 0, f"vite ssr 번들 실패:\n{build.stdout}\n{build.stderr}"
+        bundle = Path(outdir) / "spreadsheet_numfmt_survey_entry.js"
+        input_path = Path(outdir) / "codes.json"
+        input_path.write_text(json.dumps(samples, ensure_ascii=False), encoding="utf-8")
+        run = subprocess.run(
+            ["node", str(bundle), str(input_path)],
+            capture_output=True,
+            text=True,
+            encoding="utf-8",
+            errors="replace",
+            timeout=60,
+        )
+        assert run.stdout.strip(), f"시험 진입이 아무 결과도 안 냄:\n{run.stderr}"
+        return json.loads(run.stdout)
+
+
+def test_real_world_format_codes_do_not_error():
+    samples = _collect_codes()
+    assert len(samples) > 30, f"실무 코드가 너무 적게 걸림: {len(samples)}"
+    results = _run_survey(samples)
+    broken = [
+        r
+        for r in results
+        if r["code"] not in KNOWN_UNSUPPORTED and (r["numErr"] or r["strErr"])
+    ]
+    assert broken == [], json.dumps(broken, ensure_ascii=False, indent=1)