<textarea/> tag "swallows" html

<textarea> is not a self-closing tag. It should be re-written as <textarea></textarea>

I am assuming you trying to have the paragraphs appear after the textarea. Try not using the textarea tag as an empty tag.

<textarea></textarea>

<p align="center">
    test
</p>
<p align="left">
   test
</p>

I believe Textarea requires an opening and closing tag - at least that's how it's presented here: textarea at w3schools