I am a UI designer, I study to improve my knowledge of UX and I have doubts about a project.
I have a modal login / registration window that works as the Etsy login / registration mode in the payment process. In the first step it contains only one field for the email address and a "Continue" button.
Then, if the email is already registered, the modal says "Welcome again" and asks the user to enter the password.
If the email is not registered on the site, the modal says "You are new here" and ask the client to create an account and enter a password.
What do you think about a solution like this? Can it be confusing for customers? Is it an unusual pattern? Thanks for your help!