diff --git a/artifacts/tx-os/src/components/editable-cell.tsx b/artifacts/tx-os/src/components/editable-cell.tsx
index 9c0b6205..b76105f5 100644
--- a/artifacts/tx-os/src/components/editable-cell.tsx
+++ b/artifacts/tx-os/src/components/editable-cell.tsx
@@ -545,9 +545,11 @@ function FormattingToolbar({
       : "bg-white text-[#0B1E3F] hover:bg-gray-100 border border-gray-200");
 
   // Position the toolbar via a portal so it escapes table cells with
-  // overflow:hidden. We try to place it above the editor, but flip below
-  // when there isn't enough room (e.g. first row of the table). We also
-  // clamp horizontally to keep it inside the viewport.
+  // overflow:hidden. Default placement is BELOW the editor; we only
+  // flip ABOVE when staying below would hide the toolbar under the iOS
+  // soft keyboard or off the bottom of the visible viewport (#581).
+  // We also clamp horizontally to keep it inside the table's scroll
+  // container (falling back to the viewport).
   const [pos, setPos] = useState<{ top: number; left: number } | null>(null);
   const [toolbarEl, setToolbarEl] = useState<HTMLDivElement | null>(null);
   const setToolbarNode = useCallback(
@@ -595,7 +597,7 @@ function FormattingToolbar({
       // swatches / Save / Cancel become unreachable on iPad. See #581.
       const vvTop = vv.offsetTop;
       const vvBottom =
-        vv.offsetTop + (vv.height || window.innerHeight);
+        vv.offsetTop + (vv.height ?? window.innerHeight);
       let top = rect.bottom + 4;
       if (top + tbHeight > vvBottom - 4) {
         const above = rect.top - tbHeight - 4;