diff --git a/Assets/PerfectWorld/Scripts/Managers/EC_InventoryUI.cs b/Assets/PerfectWorld/Scripts/Managers/EC_InventoryUI.cs
index f3773eb874..33ca375e57 100644
--- a/Assets/PerfectWorld/Scripts/Managers/EC_InventoryUI.cs
+++ b/Assets/PerfectWorld/Scripts/Managers/EC_InventoryUI.cs
@@ -211,6 +211,8 @@ namespace BrewMonster.Scripts.Managers
         {
             if (splitPanelRoot != null)
                 splitPanelRoot.SetActive(show);
+            if (IsSplitCloseButtonOnModal() && splitCloseButton != null)
+                splitCloseButton.gameObject.SetActive(show);
         }
 
         /// <summary>
@@ -1197,6 +1199,50 @@ namespace BrewMonster.Scripts.Managers
         private void ShowDetailPanel(bool show)
         {
             EC_UIUtility.ShowPanel(detailPanelRoot.gameObject, show);
+            if (!show)
+                RefreshSplitControlsVisibility(0, null);
+        }
+
+        /// <summary>
+        /// Split affordance only for main bag stacks (same as <see cref="SeparateSelectedStack"/>).
+        /// If <c>splitCloseButton</c> is parented under <c>splitPanelRoot</c>, its visibility follows the modal (not this rule).
+        /// </summary>
+        private bool IsSplitCloseButtonOnModal()
+        {
+            return splitPanelRoot != null && splitCloseButton != null &&
+                   splitCloseButton.transform.IsChildOf(splitPanelRoot.transform);
+        }
+
+        private bool CanShowSplitControls(byte package, EC_IvtrItem item)
+        {
+            if (item == null)
+                return false;
+            if (package != PKG_INVENTORY)
+                return false;
+            int n = item.GetCount();
+            if (n < 2 && item.m_iCount >= 2)
+                n = item.m_iCount;
+            return n >= 2;
+        }
+
+        /// <summary>
+        /// <c>splitOpenButton</c>: show only when a splittable main-bag stack is selected (detail panel).
+        /// <c>splitCloseButton</c>: if it lives on the split modal, show only when modal is open; else same as open (detail-placed cancel).
+        /// </summary>
+        private void RefreshSplitControlsVisibility(byte package, EC_IvtrItem item)
+        {
+            bool canSplit = CanShowSplitControls(package, item);
+
+            if (splitOpenButton != null)
+                splitOpenButton.gameObject.SetActive(canSplit);
+
+            if (splitCloseButton != null)
+            {
+                if (IsSplitCloseButtonOnModal())
+                    splitCloseButton.gameObject.SetActive(splitPanelRoot != null && splitPanelRoot.activeSelf);
+                else
+                    splitCloseButton.gameObject.SetActive(canSplit);
+            }
         }
 
         private Button GetButtonForSlot(byte package, int slot)
@@ -1297,6 +1343,8 @@ namespace BrewMonster.Scripts.Managers
             // Show panel first
             // 先显示面板
             ShowDetailPanel(true);
+            // After detail root is active so child buttons actually appear (fixes split controls under inactive parents).
+            RefreshSplitControlsVisibility(package, item);
             //Refresh the position of the description text. Used for UI logic purpose.
             descriptionText.tmp.gameObject.GetComponent<ItemInfoText>()?.RefreshLayout();