Adapt layout for dynamic island

Adjust top margin based on platform to accommodate the dynamic island on iOS devices.

src/main.tsx

@@ -1,5 +1,14 @@
-import { createRoot } from 'react-dom/client'
-import App from './App.tsx'
+import React from 'react'
+import ReactDOM from 'react-dom/client'
+import App from './App'
 import './index.css'
+import { applySafeAreaInsets } from './utils/safeArea';
 
-createRoot(document.getElementById("root")!).render(<App />);
+// 안전 영역 CSS 변수 초기화
+applySafeAreaInsets();
+
+ReactDOM.createRoot(document.getElementById('root')!).render(
+  <React.StrictMode>
+    <App />
+  </React.StrictMode>,
+)