Intro component with sign up form

I found the JS a bit tricky at first. I saw that the examples most likely used block elements/event listeners to toggle classes like 'hidden'. At that time I thought it would be a better solution to inject some elements and have some css baked in to position them. I've seen it used in a tutorial in the past and it seemed like an easy way to add an element to be used for something like an error message. I should also mentioned that this tutorial briefly went over security risks with it. So when I ran into a bit of difficulty wanting to remove the injected HTML I went down a rabbit hole of ways to safely inject HTML. Turns out it's just a really not good idea and should be avoided altogether if possible. So I went back to original thought and this is the solution I developed.