Revert "refactor sticky scroll handler"

This reverts commit da9d7f8eb3.

src/components/FloatingButton/FloatingButton.tsx

@@ -15,28 +15,10 @@ export function FloatingButton() {
   const { showScrollTop } = useScrollHandler();
 
   const scrollToTop = useCallback(() => {
-    // Use a more stable approach to find the scroll container
-    const findScrollContainer = () => {
-      const antApp = document.querySelector('.ant-app') as HTMLElement;
-      if (antApp && antApp.scrollHeight > antApp.clientHeight) {
-        return antApp;
-      }
-      
-      const appContainer = document.querySelector('[class*="App"]') as HTMLElement;
-      if (appContainer && appContainer.scrollHeight > appContainer.clientHeight) {
-        return appContainer;
-      }
-      
-      return document.documentElement;
-    };
-    
-    const scrollContainer = findScrollContainer();
-    if (scrollContainer) {
-      scrollContainer.scrollTo({
-        top: 0,
-        behavior: "smooth",
-      });
-    }
+    window.scrollTo({
+      top: 0,
+      behavior: "smooth",
+    });
   }, []);
 
   return (