diff --git a/artifacts/tx-os/src/components/executive-meetings/upcoming-meeting-alert.tsx b/artifacts/tx-os/src/components/executive-meetings/upcoming-meeting-alert.tsx
index 9f042832..f65cef3f 100644
--- a/artifacts/tx-os/src/components/executive-meetings/upcoming-meeting-alert.tsx
+++ b/artifacts/tx-os/src/components/executive-meetings/upcoming-meeting-alert.tsx
@@ -958,7 +958,10 @@ function CascadePromptBlock({
               ellipsis instead of pushing the times off-screen, and
               the From → To column always fits on one line. */}
           <colgroup>
-            <col className="w-12" />
+            {/* w-20 leaves room for the Arabic header "رقم الاجتماع"
+                with whitespace-nowrap; w-12 was too tight at common
+                font sizes. */}
+            <col className="w-20" />
             <col />
             <col className="w-40" />
           </colgroup>
diff --git a/artifacts/tx-os/tests/executive-meetings-upcoming-alert.spec.mjs b/artifacts/tx-os/tests/executive-meetings-upcoming-alert.spec.mjs
index 6e993ec7..58118b89 100644
--- a/artifacts/tx-os/tests/executive-meetings-upcoming-alert.spec.mjs
+++ b/artifacts/tx-os/tests/executive-meetings-upcoming-alert.spec.mjs
@@ -1291,6 +1291,84 @@ test("Upcoming-meeting alert: details panel renders attendees as numbered tables
   await expect(secondGroupRows.first()).toContainText("Internal One");
 });
 
+test("Postpone dialog: cascade-followers table sits fully inside the dialog (no horizontal spill, RTL)", async ({
+  page,
+}) => {
+  // #485: regression for the cascade preview overlapping the dialog
+  // edge in Arabic. Seed a primary meeting + two followers later in
+  // the same day so the cascade prompt definitely fires after
+  // confirming a postpone, then assert the followers-list bounding
+  // box sits within the dialog's bounding box.
+  await setLang(page, "ar");
+  const primary = await insertImminentMeeting({
+    titleAr: `${TEST_TAG} cascade-layout primary AR ${"بعنوان طويل جداً يكفي لاختبار القص بالنقاط في عمود العنوان داخل اللوحة"}`,
+    titleEn: `${TEST_TAG} cascade-layout primary EN with a sufficiently long title to verify column truncation`,
+    deltaMins: 3,
+  });
+  await insertImminentMeeting({
+    titleAr: `${TEST_TAG} cascade-layout follower-1 AR`,
+    titleEn: `${TEST_TAG} cascade-layout follower-1 EN`,
+    deltaMins: 30,
+  });
+  await insertImminentMeeting({
+    titleAr: `${TEST_TAG} cascade-layout follower-2 AR`,
+    titleEn: `${TEST_TAG} cascade-layout follower-2 EN`,
+    deltaMins: 60,
+  });
+  await page.setViewportSize({ width: 1280, height: 800 });
+  await loginViaUi(page, "admin", "admin123");
+  await page.goto("/");
+  await expect(page.getByTestId("upcoming-meeting-alert")).toBeVisible({
+    timeout: 15_000,
+  });
+  await page.getByTestId("alert-postpone").click();
+  const dialog = page.getByTestId("postpone-dialog");
+  await expect(dialog).toBeVisible();
+  await page.getByTestId("postpone-chip-10").click();
+  await expect(page.getByTestId("postpone-confirm-block")).toBeVisible();
+  await page.getByTestId("postpone-confirm-yes").click();
+
+  // Cascade prompt must appear with this seeding (two later meetings
+  // on the same day). Geometry checks then verify no spill.
+  const followersList = page.getByTestId("cascade-followers-list");
+  await expect(followersList).toBeVisible({ timeout: 8_000 });
+
+  const dialogBox = await dialog.boundingBox();
+  const tableBox = await followersList.boundingBox();
+  expect(dialogBox).not.toBeNull();
+  expect(tableBox).not.toBeNull();
+  // Table must sit fully inside the dialog (1px tolerance for
+  // sub-pixel rounding).
+  expect(tableBox.x + 1).toBeGreaterThanOrEqual(dialogBox.x);
+  expect(tableBox.x + tableBox.width).toBeLessThanOrEqual(
+    dialogBox.x + dialogBox.width + 1,
+  );
+
+  // The truncating title cell must not push the times column out of
+  // the dialog. Check the first follower row's last cell (times).
+  const lastCell = page
+    .locator('[data-testid^="cascade-follower-"]')
+    .first()
+    .locator("td")
+    .last();
+  const lastBox = await lastCell.boundingBox();
+  expect(lastBox).not.toBeNull();
+  expect(lastBox.x + lastBox.width).toBeLessThanOrEqual(
+    dialogBox.x + dialogBox.width + 1,
+  );
+
+  // Politely back out so this seeded meeting doesn't preempt later
+  // tests' alerts.
+  await page.getByTestId("cascade-back").click();
+  await pool.query(
+    `UPDATE executive_meetings
+        SET start_time = (start_time::time + interval '2 hours')::time,
+            end_time   = (end_time::time   + interval '2 hours')::time
+      WHERE id = $1`,
+    [primary.id],
+  );
+});
+
 test("Postpone dialog: reschedule date / start / end inputs sit fully inside the dialog (no clipping at desktop width, RTL)", async ({
   page,
 }) => {