refactor

frontend/src/pages/Register.jsx

@@ -1,26 +1,26 @@
 import React, { useState } from 'react';
 import { useNavigate, Link } from 'react-router-dom';
+import toast from 'react-hot-toast';
 import { useAuth } from '../AuthContext';
 
 export default function Register() {
   const [email, setEmail] = useState('');
   const [username, setUsername] = useState('');
   const [password, setPassword] = useState('');
-  const [error, setError] = useState('');
   const [loading, setLoading] = useState(false);
   const { register } = useAuth();
   const navigate = useNavigate();
 
   const handleSubmit = async (e) => {
     e.preventDefault();
-    setError('');
     setLoading(true);
 
     try {
       await register(email, username, password);
+      toast.success('Account created successfully!');
       navigate('/challenges');
     } catch (err) {
-      setError(err.message);
+      toast.error(err.message || 'Registration failed');
     } finally {
       setLoading(false);
     }
@@ -62,7 +62,6 @@ export default function Register() {
               minLength={6}
             />
           </div>
-          {error && <div className="error">{error}</div>}
           <button type="submit" className="btn btn-primary" style={{ width: '100%', marginTop: '1rem' }} disabled={loading}>
             {loading ? 'Creating account...' : 'Register'}
           </button>