Add a login/account system that is not generated through iframe

Site URL: https://www.lerligisa.com/

Hi, 

I have built a multilingual website (English, French), and I have tried to adjust the Customer Account language depending on whether a French or English speaking customer is logging in, by using custom code, but I am seeing issues, as the Customer Account feature is using iframe. Is there a way to add a login/account system that is not generated through iframe? 

Thanks, 

Eva