Problems with blockquote

I installed a theme called photopaper. It’s great and everything but I can’t fix a problem with the blockquote. No matter what I do, it is always aligned to the left and I want it to occupy the whole space of the post. Also, because of this problem, when I start a new paragraph, it goes right to the side of the blockquote… How can I solve this? I have no code for blockquote in the style.css file whatsoever.

Here’s a link of a post in my website with this problem:

http://www.papoaria.com.br/teste-de-blockquote/