Article width!

Good evening.

I have a question about the width of the article. This is a current example of my web:

https://www.solotriplesacb.com/2015/10/movistar-estudiantes-ficha-vladimir-stimac/

I need the text doesn’t extends both left and right, and that the main column where the text will be narrower.

The code is very extensive and don’t know where is that option.

Thanks in advance!