Wordpress how to remove article element white background

I'm trying to remove the white-background of wordpress Article (page), NOT the body background, the element's background. I would that the article text has no white background, but only the body background.

I've tryed so many "external css" but no one worked for me.

   article.post-1 { //just an example, I've tryed many other elements
     background-color: transparent;
   }

https://i.imgur.com/gJtqjpP.jpg You can see the white background behind the TEXT, i would remove that white and see the TEXT directly on the background image. It's in the homepage.

#html #wordpress