Is there a way to remove margins/padings for specific pages in Hugo Academic?

I have iframe object that I want to be at the full width of the page without margins (screenshot attached). I added a css code to .md file, but 0 padding is already where the iframe is at the moment, so I can move it the right, but not to the left.

Can it be adjusted for the specific objects/pages?

iframe {
  margin-left: 0;
  padding-left: 0;