diff --git a/frontend/src/App.css b/frontend/src/App.css
index e51b43b..9ec8e4d 100644
--- a/frontend/src/App.css
+++ b/frontend/src/App.css
@@ -1794,20 +1794,20 @@ html.desktop-client .tmb-logo-version {
 
 /* 사용자 정의 탭 편집 */
 .ind-tab-editor-overlay {
-  position: absolute;
+  position: fixed;
   inset: 0;
-  z-index: 10;
+  z-index: 2100;
   display: flex;
   align-items: center;
   justify-content: center;
+  padding: 16px;
   background: rgba(0, 0, 0, 0.55);
-  border-radius: inherit;
 }
 .ind-tab-editor {
   display: flex;
   flex-direction: column;
-  width: min(420px, calc(100% - 24px));
-  max-height: calc(100% - 24px);
+  width: min(420px, calc(100vw - 24px));
+  max-height: calc(100vh - 32px);
   background: var(--bg2);
   border: 1px solid var(--border);
   border-radius: 8px;
diff --git a/frontend/src/components/IndicatorCustomTabEditor.tsx b/frontend/src/components/IndicatorCustomTabEditor.tsx
index bfe9388..147a0a8 100644
--- a/frontend/src/components/IndicatorCustomTabEditor.tsx
+++ b/frontend/src/components/IndicatorCustomTabEditor.tsx
@@ -1,4 +1,5 @@
 import React, { useEffect, useMemo, useState } from 'react';
+import ReactDOM from 'react-dom';
 import { INDICATOR_REGISTRY, type IndicatorDef } from '../utils/indicatorRegistry';
 import { MAIN_INDICATOR_LABELS } from '../utils/indicatorMainTab';
 
@@ -76,7 +77,7 @@ const IndicatorCustomTabEditor: React.FC<IndicatorCustomTabEditorProps> = ({
     onSave(trimmed, ordered);
   };
 
-  return (
+  return ReactDOM.createPortal(
     <div
       className="ind-tab-editor-overlay"
       onMouseDown={e => { if (e.target === e.currentTarget) onClose(); }}
@@ -163,7 +164,8 @@ const IndicatorCustomTabEditor: React.FC<IndicatorCustomTabEditorProps> = ({
           </button>
         </div>
       </div>
-    </div>
+    </div>,
+    document.body,
   );
 };