diff --git a/A00_Common/design/design_page.css b/A00_Common/design/design_page.css
index d4b2ff545..14c44dba2 100644
--- a/A00_Common/design/design_page.css
+++ b/A00_Common/design/design_page.css
@@ -66,7 +66,8 @@
   position: absolute;
   top: 4px;
   left: var(--spacing-8);
-  z-index: 4;
+  /* 고정 Y축(z5 · 불투명) 위 — 아래면 축 띠에 가려짐 */
+  z-index: 6;
 }
 
 /* 새 창으로 뗀 유토곡선 · 배수유역 판 — 창 전체를 채움 · 높이 · 폭 끌기와 접기 손잡이는 감춤. */
diff --git a/resources/tester/test_354_1_masshaul_own_panel.py b/resources/tester/test_354_1_masshaul_own_panel.py
index 2fa426979..db6d58359 100644
--- a/resources/tester/test_354_1_masshaul_own_panel.py
+++ b/resources/tester/test_354_1_masshaul_own_panel.py
@@ -137,6 +137,6 @@ def test_창_분할_판_좌상단():
     assert "massOverlay.append(button);" in popout
     assert "home: () => massHandle.before(massOverlay)," in popout
     page = read("A00_Common/design/design_page.css")
-    assert "position: absolute;" in css_block(
-        page, ".b05-profile__masshaul-overlay > .b05-subpanel__popout"
-    )
+    button = css_block(page, ".b05-profile__masshaul-overlay > .b05-subpanel__popout")
+    # 고정 Y축(z5) 위 — 아래면 단추가 축 띠에 가려짐
+    assert "position: absolute;" in button and "z-index: 6;" in button