Responsive Sign-up form with input validate

I think the markup it's too long for such a simple task. I've noticed that if the input, the label and the error image was in the same image it would take less code to show the same thing. I used the input event to remove the error message when the user tries to fix an wrong field because the browser focus on the email field when it's wrong, and I did find out how to disable this without change the input type from email to text. Any feedback will be appreciated.