cleanup

frontend/src/app/PanelManagerContext.tsx

@@ -98,12 +98,13 @@ const persistWidth = (panel: PanelKey, value: number): void => {
   window.localStorage.setItem(STORAGE_KEYS[panel], String(Math.round(value)));
 };
 
-const applyPanelWidthToRoot = (panel: PanelKey, width: number): void => {
+const applyPanelWidthToRoot = (panel: PanelKey, width: number, active: boolean): void => {
   if (!Number.isFinite(width)) {
     return;
   }
   const varName = panel === 'sidebar' ? '--sidebar-width' : '--detail-panel-width';
-  document.documentElement.style.setProperty(varName, `${width}px`);
+  const resolvedValue = panel === 'detail' && !active ? '0px' : `${width}px`;
+  document.documentElement.style.setProperty(varName, resolvedValue);
 };
 
 interface PanelManagerProviderProps {
@@ -132,13 +133,13 @@ export const PanelManagerProvider: React.FC<PanelManagerProviderProps> = ({ chil
 
   useEffect(() => {
     panelWidthsRef.current.sidebar = sidebarWidth;
-    applyPanelWidthToRoot('sidebar', sidebarWidth);
+    applyPanelWidthToRoot('sidebar', sidebarWidth, true);
   }, [sidebarWidth]);
 
   useEffect(() => {
     panelWidthsRef.current.detail = detailWidth;
-    applyPanelWidthToRoot('detail', detailWidth);
-  }, [detailWidth]);
+    applyPanelWidthToRoot('detail', detailWidth, detailPanelOpen);
+  }, [detailWidth, detailPanelOpen]);
 
   const handlePanelLayoutChange = useCallback((
     panel: PanelKey,
@@ -187,7 +188,6 @@ export const PanelManagerProvider: React.FC<PanelManagerProviderProps> = ({ chil
         setDetailWidthState((prev) => (prev === clamped ? prev : clamped));
       }
       panelWidthsRef.current[panel] = clamped;
-      applyPanelWidthToRoot(panel, clamped);
       if (commit) {
         preferredPanelWidthsRef.current[panel] = clamped;
         persistWidth(panel, clamped);