Why did my #form-outer stop expanding?

My codpen: https://codepen.io/Jediadam/pen/xzdmPL

What exactly do you mean? Add details to your question.

I want the #form-outer to expand down the page as I type. I think it was doing that before but now it’s not.

You can’t do it with CSS. You have to use JavaScript and textarea tag. You can see an example here: textarea expand as you type.
If you want to expand inputs I haven’t answer on it.

You accidentally closed off the div too soon. Delete the </div> below the following line in your html.

<p> *Only used to determine if high or low class people benefit more from coding.</p>

That just gets rid of all the white.

I just checked your pen again, and you did not delete the </div> which I specified above.

I chose not to save it that way because every time I delete the div it gets rid of all the white.

I think you may not be talking about the same extra </div> to which I am referring. When I comment out the </div> on line 32 of your html, the white section expands down the way you want it to. Watch below as I comment out line 32 of the html.