prepare("SELECT * FROM users WHERE username = ?"); $stmt->execute([$username]); $user = $stmt->fetch(); if ($user && password_verify($password, $user['password'])) { $_SESSION['user_id'] = $user['id']; $_SESSION['username'] = $user['username']; header("Location: dashboard.php"); // Seite nach dem Login exit; } else { $error = "Ungültige Login-Daten!"; } } ?>