fix: styles

src/App.tsx

@@ -9,6 +9,7 @@ import {
 import './App.css';
 import { useTranslation } from 'react-i18next';
 import { LanguageManager } from './components/LanguageManager';
+import { UserCompletionForm } from './features/authentication/components/UserCompletionForm';
 
 function App() {
   const { t } = useTranslation();
@@ -18,6 +19,7 @@ function App() {
     <>
       <CssBaseline />
       <LanguageManager />
+      <UserCompletionForm />
       <div style={{ padding: '16px' }}>
         <Typography variant="h3">{t('helloWorld')}</Typography>
         <Box