Pod Request Access Landing Page with SASS and Javascript

Hi guys, will appreciate any comments and feedback for this project. I'm focusing on javascript now, so I am hoping to get some feedback on that, eventhough the code for this is just tiny.

I added a custom border while user is typing the email, to signal if it is still wrong or if email is in the correct format. :)

For the custom text to appear when user email input is wrong, I used a " form::after " to inject the message into the content. Is this a good way to do it? Or better to create a blank div and update innerHTML? However the div interfered with the grid I had set up, so I thought the former was a better solution.