I did something a little different. I moved the "leave a comment" button above the text box. I can type perfectly fine in the text box, but the input button won't work. Help, please? I added red borders to make it more visible.

I think you'd be better off positioning them (position:absolute with top and left) rather than using margins to switch them around.

Since the comment box comes before the post button in the html it's layered above it and the margin seems to cover the post button.

That worked perfectly, thank you!