Thank you very much for the reply. You know there are .cls files ‘classes’, and .sty files ‘style files’ for a journal template (such as AMS journal or Elsvier journal), and .bst ‘bib style files’.
On the other hand, it seems that the ‘Theorem environment, Proposition environment’ have been defined in this plugin, so I should use the defined environment and cannot use the one I defined already in a latex file.
It works well if I just write Latex code using this plugin, but I am trying to show the latex code in the style I want to use (like the Elsvier journal style or others). I just wander whether I change class style when I write a blog, and how if it is possible.