Responsive Intro Component with Signup Form

What challenges did you encounter, and how did you overcome them?

Hi everyone, I have just completed another project. But there is a bug:

1. Unless the email field is empty or in the correct email format, it doesn't display an error message for all input fields (First Name, Last Name, and Password) including itself (for Email Address).
2. And also I would love to hear your feedback on how to change the invalid email format's color to red.

Thanks in advance for your feedback.