diff --git a/resources/tester/helper_202_1_fill_below.cjs b/resources/tester/helper_202_1_fill_below.cjs
index 73fd59feb..190b7517c 100644
--- a/resources/tester/helper_202_1_fill_below.cjs
+++ b/resources/tester/helper_202_1_fill_below.cjs
@@ -44,17 +44,19 @@ const sty = (n) => ({
   paddingBottom: n.css.paddingBottom ?? "0px",
   borderBottomWidth: n.css.borderBottomWidth ?? "0px",
   marginBottom: n.css.marginBottom ?? "0px",
+  position: n.css.position ?? "static",
 });
 const box = { exports: {} };
-new Function("exports", "module", "require", "window", "document", "getComputedStyle", "ResizeObserver", js)(
-  box.exports,
-  box,
-  (p) => (p.endsWith(".css") ? {} : require(p)),
-  win,
-  { body: null },
-  sty,
-  RO,
-);
+new Function(
+  "exports",
+  "module",
+  "require",
+  "window",
+  "document",
+  "getComputedStyle",
+  "ResizeObserver",
+  js,
+)(box.exports, box, (p) => (p.endsWith(".css") ? {} : require(p)), win, { body: null }, sty, RO);
 const m = box.exports;
 
 // 문서: body(padding-bottom 8) > card(padding-bottom 12 · gap 8) > [root][avg 20][info 30][hint 40]
@@ -81,4 +83,9 @@ hint.height = 60;
 observers.forEach((o) => o.fn());
 out.afterHintGrow = parseFloat(root.style.maxHeight);
 out.firstMinusGrow = out.first - 20;
+
+// 열린 창 가림막(body 끝 · position fixed · 창 높이) = 아래 자리에 안 셈(707-5)
+link(body, card, el("backdrop", { position: "fixed" }, 900));
+out.belowWithModal = m.spaceBelow(root);
+out.belowAfterGrow = 3 * 8 + 20 + 30 + 60 + 12 + 8;
 console.log(JSON.stringify(out));
diff --git a/resources/tester/test_202_1_table_hint_bottom.py b/resources/tester/test_202_1_table_hint_bottom.py
index 5d89460f6..f79393036 100644
--- a/resources/tester/test_202_1_table_hint_bottom.py
+++ b/resources/tester/test_202_1_table_hint_bottom.py
@@ -177,3 +177,4 @@ def test_창_끝까지_셈에_아래_안내_줄_포함():
     assert r["below"] == r["belowExpected"] == 134  # 아래 줄 · 안내 줄 둘 + 여백
     assert r["bottom"] == r["viewport"]  # 문서 맨 아래 = 창 끝 → 페이지 스크롤 0
     assert r["afterHintGrow"] == r["firstMinusGrow"]  # 안내 줄이 늘면 표 칸이 그만큼 줄어듦
+    assert r["belowWithModal"] == r["belowAfterGrow"]  # 열린 창 가림막(fixed) = 아래 자리 아님
diff --git a/ui_template/ui_template_data_table.ts b/ui_template/ui_template_data_table.ts
index 6fd8c5c2d..7ffe3a975 100644
--- a/ui_template/ui_template_data_table.ts
+++ b/ui_template/ui_template_data_table.ts
@@ -410,7 +410,8 @@ export function spaceBelow(el: HTMLElement): number {
     for (let s = node.nextElementSibling; s; s = s.nextElementSibling) {
       const h = s.getBoundingClientRect().height;
       const m = getComputedStyle(s); // 203 형제 위아래 바깥 여백도(B09 안내 글 margin-top)
-      if (h) sum += h + gap + px(m.marginTop) + px(m.marginBottom);
+      const out = m.position === "fixed" || m.position === "absolute"; // 열린 창 가림막 · 알림 = 자리 안 씀
+      if (h && !out) sum += h + gap + px(m.marginTop) + px(m.marginBottom);
     }
     sum += px(own.marginBottom) + px(around.paddingBottom) + px(around.borderBottomWidth);
   }