diff --git a/B05_Profile/B05_Profile_UI_Structures_Groups.ts b/B05_Profile/B05_Profile_UI_Structures_Groups.ts
index 63b1afc19..71bdf7beb 100644
--- a/B05_Profile/B05_Profile_UI_Structures_Groups.ts
+++ b/B05_Profile/B05_Profile_UI_Structures_Groups.ts
@@ -21,7 +21,8 @@ import { hiddenFormKeys } from "./B05_Profile_UI_Drainage_Facility_Merge";
 import { buildSummaryRow, type SummaryRow } from "./B05_Profile_UI_Structures_Summary_Row";
 import { isOptionVisible } from "./B05_Profile_UI_Structures_Summary";
 import { SHAPE_FIELDS, shapeFields, shapeKey } from "./B05_Profile_UI_Structures_Define";
-import { field, numberInput } from "./B05_Profile_UI_Structures_Fields";
+import { numberInput } from "./B05_Profile_UI_Structures_Fields";
+import { grid, group as boxOf, labeled, stepper } from "./B05_Profile_UI_Drainage_Facility_Fields";
 import { STRUCTURE_SPECS } from "../A00_Common/design/design_structure_pipe";
 import {
   GROUP_JOIN,
@@ -126,13 +127,11 @@ export function createGroupBoxes(): GroupBoxes {
       );
       for (const group of groups) {
         const keys = hiddenFormKeys(facility, group.options);
-        const box = document.createElement("fieldset");
-        box.className = "b05-structure__group b05-structure__optgroup";
-        box.dataset.b05Group = group.id;
-        const legend = document.createElement("legend");
-        legend.textContent = group.name;
-        const body = document.createElement("div");
-        body.className = "b05-structure__grid";
+        // 상자 꼴 = 명세 컨테이너(`design_structure_form`)와 같은 조각 — 제목 · 몸통 · 격자 · 잇기 줄(52-18)
+        const box = boxOf(group.name);
+        box.root.classList.add("b05-structure__optgroup");
+        box.root.dataset.b05Group = group.id;
+        const body = grid();
         for (const scope of scopes) {
           const marked = [...scope.querySelectorAll<HTMLElement>("[data-option-keys]")];
           // 지금 숨은 칸(다른 시설 몫 · 안 고른 갈래)은 그 자리에 둠 — 같은 키 칸이 두 벌 옮겨 오지 않게
@@ -180,23 +179,24 @@ export function createGroupBoxes(): GroupBoxes {
             handlers?.change?.();
           });
           shapeInputs.set(key, input);
-          body.append(field(shape.label, input));
+          body.append(labeled(shape.label, stepper(input, 0.1)));
         }
         if (!body.childElementCount) {
           const none = document.createElement("p");
           none.className = "b05-structure__owner-note";
-          none.textContent = "옵션 없음 — 집계 항목만 지정";
+          none.textContent = "옵션 없음 — 구조물 조합만 지정";
           body.append(none);
         }
         const row = buildSummaryRow();
+        row.root.querySelector(".b05-structure__summary-label")!.textContent = "구조물 조합";
         row.set(items[group.id] ?? null);
         row.bind({
           pick: () => handlers?.pick(group.id),
           clear: () => handlers?.clear(group.id),
         });
         rows.set(group.id, row);
-        box.append(legend, body, row.root);
-        boxes.push(box);
+        box.body.append(body, row.root);
+        boxes.push(box.root);
         bodies.push(body);
       }
       const stale =
diff --git a/B05_Profile/B05_Profile_UI_Structures_Panel_Options.ts b/B05_Profile/B05_Profile_UI_Structures_Panel_Options.ts
index 650aef741..320f151ef 100644
--- a/B05_Profile/B05_Profile_UI_Structures_Panel_Options.ts
+++ b/B05_Profile/B05_Profile_UI_Structures_Panel_Options.ts
@@ -20,6 +20,7 @@ import {
   staleValues,
 } from "./B05_Profile_UI_Structures_Define";
 import { FORM_OPTION_KEYS } from "./B05_Profile_UI_Drainage_Facility_Merge";
+import { stepper } from "./B05_Profile_UI_Drainage_Facility_Fields";
 import { STRUCTURE_SPECS } from "../A00_Common/design/design_structure_pipe";
 import { paintStructureSpec, specOwnedKeys } from "./B05_Profile_UI_Structures_Spec";
 import { solveSplit, specKeys, type SplitRole } from "../A00_Common/design/design_structure_spec";
@@ -97,7 +98,15 @@ export function renderOptionFields(
     const name = (c: string): string => type.spec_names?.[`${option.key}=${c}`] ?? c;
     const input = optionControl(option, values[option.key], name);
     const label = `${option.unit ? `${option.label} (${option.unit})` : option.label}${option.not_in_table ? " · 표에 안 쓰임" : ""}`;
-    const wrap = field(label, input, option.default_basis);
+    // 정의 그룹 상자로 옮겨 갈 숫자 칸 = 명세 컨테이너와 같은 [－][숫자][＋](52-18)
+    const grouped =
+      option.input === "number" && !!type.groups?.some((g) => g.options.includes(option.key));
+    const wrap = field(
+      label,
+      grouped ? stepper(input as HTMLInputElement, 0.1) : input,
+      option.default_basis,
+    );
+    if (grouped) wrap.htmlFor = input.id; // 라벨 대상 = 숫자 칸(첫 버튼으로 새지 않게)
     wrap.dataset.optionKeys = option.key; // 옵션 그룹 상자가 이 표식으로 칸을 옮김(PLAN 46-3)
     // 배치 격자(48-3) — 정의 `배치` 의 줄 · 칸 · 너비 · 없으면 흐름대로
     const place = gridPlace(type.spots?.[option.key], columns);
diff --git a/B05_Profile/B05_Profile_UI_Style_Structures.css b/B05_Profile/B05_Profile_UI_Style_Structures.css
index 0d374f4dc..ac4c69368 100644
--- a/B05_Profile/B05_Profile_UI_Style_Structures.css
+++ b/B05_Profile/B05_Profile_UI_Style_Structures.css
@@ -499,25 +499,13 @@
 }
 
 .b05-structure__optgroup {
-  display: flex;
-  flex-direction: column;
-  gap: 6px;
   min-width: 0; /* 긴 집계 항목 이름이 상자를 패널 밖으로 밀지 않게(fieldset 최소 폭 · 52-9) */
 }
 
-.b05-structure__optgroup > legend {
-  font-weight: 600;
-  opacity: 1;
-}
-
 .b05-structure__optgroup .is-option-hidden {
   display: none;
 }
 
-.b05-structure__optgroup > .b05-structure__grid.is-locked {
-  opacity: 0.5;
-}
-
 /* 구조물 정의 규칙(PLAN 48-4)이 가린 칸 — 그룹 상자로 옮겨 가도 같은 표식 */
 .b05-structure-section .is-rule-hidden {
   display: none;