With modals I load an article. The article loads the core Login module by using {loadposition}. After entering the login credentials, the user gets redirected to another article. But this page is loaded inside modals instead of modals does close and page is loaded in main window.
Articles will be opened in iframes.
You can either set the target on the form to _top or _parent.
Or place the module as inline content with the help of Modules Anywhere.
I want the same you have here on your website: If I'm not logged in and I click the login link, the login form opens in a modal. After I have entered username and PW and click green login button, the modal closes ansd I get redirected.