diff --git a/M02_MasterTemplete/M02_MasterTemplete_UI_Main.ts b/M02_MasterTemplete/M02_MasterTemplete_UI_Main.ts
index 13630fac5..77d6b3146 100644
--- a/M02_MasterTemplete/M02_MasterTemplete_UI_Main.ts
+++ b/M02_MasterTemplete/M02_MasterTemplete_UI_Main.ts
@@ -130,8 +130,8 @@ export function createMain(
   const title = el("h2", { className: "m02-main__title", text: L("M02_PickTemplate") });
   const reload = createButton({ label: L("M02_Reload"), variant: "ghost" });
   const save = createButton({ label: L("M02_Save"), variant: "filled" });
-  // 구조물 도면 · 면적산출 상세 화면 → 구조물집계표(그 열 고른 채)
-  const back = createButton({ label: L("M02_Back"), variant: "ghost", size: "sm" });
+  // 구조물 도면 · 일위대가 · 면적산출 상세 화면 → 구조물집계표(그 열 고른 채) · 일반 단추(43-5 · 알약 · ghost 아님)
+  const back = createButton({ label: L("M02_Back") });
   const slot = el("div", { className: "m02-main__slot" }); // 도면 양식의 작도 영역 칸이 들어옴
   const notice = el("div", { className: "m02-main__notice", attrs: { hidden: "" } });
   const host = el("div", { className: "m02-main__host" });
diff --git a/resources/tester/test_m02_structure_panel.py b/resources/tester/test_m02_structure_panel.py
index be79312be..d73ce71e0 100644
--- a/resources/tester/test_m02_structure_panel.py
+++ b/resources/tester/test_m02_structure_panel.py
@@ -238,3 +238,10 @@ def test_상세_화면_돌아가기는_집계표로_그_열_고른_채():
     body = main.split('back.addEventListener("click"')[1]
     assert "confirmLeave()" in body and "STRUCTURE_TABLE" in body
     assert "sheet?.selectColumn(column)" in body
+
+
+def test_상세_머리_돌아가기는_일반_단추():
+    """43-5 — 도면 · 일위대가 · 면적산출 상세 머리 [돌아가기] = 공용 기본 단추(filled · 같은 높이 ·
+    알약 · ghost · sm 아님) · 대비는 ui_checks/43-5 시나리오(어두움 8.01)."""
+    main = _text(MAIN)
+    assert 'const back = createButton({ label: L("M02_Back") });' in main
diff --git a/resources/tester/ui_checks/43-5_돌아가기_대비.js b/resources/tester/ui_checks/43-5_돌아가기_대비.js
new file mode 100644
index 000000000..7207f3c96
--- /dev/null
+++ b/resources/tester/ui_checks/43-5_돌아가기_대비.js
@@ -0,0 +1,96 @@
+/* 43-5 · E1 — 도면 · 일위대가 · 면적산출 상세 머리 [돌아가기] 꼴 · 머리 단추 글자 대비(밝음 · 어두움)
+ * 시작 화면: M02 마스터 템플릿 · 마스터 층(#/m02-master-template?open=구조물조합&root=master) · 시스템 관리자
+ * 부르는 법: orca eval --expression "$(cat 이 파일)" (async 식 · JSON 글을 돌려줌)
+ * 기대 수치:
+ *   - 세 상세 모두 back.cls = "ui-btn ui-btn--filled"(ghost · sm 없음) · back.h = 머리 다른 단추 높이(±1px)
+ *   - 밝음 · 어두움(앱 ☾ 단추) 모두 머리 보이는 단추 대비 ≥ 4.5
+ *   - 끝나면 처음 테마로 되돌림(theme.end = theme.start)
+ * ⚠ 단추 color 전환(120ms)이 ORCA 탭에선 0ms 에 멈춰 옛 색이 읽힘(1.11 착오 · E1) — 재는 동안 전환을 끔
+ */
+(async () => {
+  const w = (ms) => new Promise((r) => setTimeout(r, ms));
+  const rgb = (s) => (s.match(/[\d.]+/g) || []).map(Number);
+  const lum = ([r, g, b]) => {
+    const f = (v) => ((v /= 255) <= 0.03928 ? v / 12.92 : ((v + 0.055) / 1.055) ** 2.4);
+    return 0.2126 * f(r) + 0.7152 * f(g) + 0.0722 * f(b);
+  };
+  /** 실제로 보이는 바탕 — 투명이면 조상으로 */
+  const bgOf = (el) => {
+    for (let e = el; e; e = e.parentElement) {
+      const c = rgb(getComputedStyle(e).backgroundColor);
+      if (c.length >= 3 && (c.length < 4 || c[3] > 0.5)) return c.slice(0, 3);
+    }
+    return [255, 255, 255];
+  };
+  const ratio = (el) => {
+    const a = lum(rgb(getComputedStyle(el).color).slice(0, 3));
+    const b = lum(bgOf(el));
+    return +((Math.max(a, b) + 0.05) / (Math.min(a, b) + 0.05)).toFixed(2);
+  };
+  const theme = () => document.documentElement.getAttribute("data-theme") || "auto";
+  const moon = () =>
+    [...document.querySelectorAll("button")].find((b) => /^[☾☀]$/.test(b.textContent.trim()));
+  const headButtons = () =>
+    [...document.querySelectorAll(".m02-main__head button")].filter(
+      (b) => !b.hidden && b.offsetParent,
+    );
+  const openRow = async (sectionTitle, prefix) => {
+    const sec = [...document.querySelectorAll(".m02-side__summary > section")].find(
+      (s) => s.querySelector("h3").textContent.trim() === sectionTitle,
+    );
+    sec.classList.remove("is-collapsed");
+    [...sec.querySelectorAll("button")].find((b) => b.textContent.startsWith(prefix)).click();
+    await w(5000);
+  };
+  const measure = () => {
+    const back = [...document.querySelectorAll(".m02-main__head button")].find(
+      (b) => b.textContent.trim() === "돌아가기",
+    );
+    const others = headButtons().filter((b) => b !== back);
+    return {
+      title: document.querySelector(".m02-main__title")?.textContent,
+      back: back && {
+        cls: back.className,
+        h: Math.round(back.getBoundingClientRect().height),
+        radius: getComputedStyle(back).borderRadius,
+      },
+      otherH: others.map((b) => Math.round(b.getBoundingClientRect().height)),
+      contrast: Object.fromEntries(
+        headButtons().map((b) => [b.textContent.trim() || b.title, ratio(b)]),
+      ),
+    };
+  };
+  const still = document.createElement("style");
+  still.textContent = "*,*::before,*::after{transition:none!important}";
+  document.head.append(still);
+  const start = theme();
+  const out = { theme: { start }, pages: {} };
+  for (const [name, sec, prefix] of [
+    ["도면", "구조물 도면", "SD-000001"],
+    ["일위대가", "일위대가", "SU-000001"],
+    ["면적산출", "면적산출", "SA-000001"],
+  ]) {
+    await openRow(sec, prefix);
+    const light = measure();
+    moon()?.click();
+    await w(400);
+    const dark = { theme: theme(), ...measure() };
+    moon()?.click();
+    await w(400);
+    out.pages[name] = { light, dark };
+  }
+  if (theme() !== start) moon()?.click();
+  out.theme.end = theme();
+  still.remove();
+  const all = Object.values(out.pages).flatMap((p) => [
+    ...Object.values(p.light.contrast),
+    ...Object.values(p.dark.contrast),
+  ]);
+  out.minContrast = Math.min(...all);
+  out.backOk = Object.values(out.pages).every(
+    (p) =>
+      p.light.back?.cls === "ui-btn ui-btn--filled" &&
+      p.light.otherH.every((h) => Math.abs(h - p.light.back.h) <= 1),
+  );
+  return JSON.stringify(out);
+})();