code to Separate buttons

Hi new here and with wordpress. I have a site that advertises my books. I have one button “click here” under each book.
This is were the problem is. I’m not clued on code so i dont know how to separate them so each sits under its own book. Did it with space bar as far as i could but its not far enough. If i keep spaceing the blue button drops to next line.

The problem is in “poetry ebooks”
The site is Rawtwig dot com

Thank you