I don't want a header/breadcrumb on blog page

Hi,

On all my pages I have selected don’t display the header. But on blog page it still appear. I guess it’s because I said in enfold admin set up blog page and assigned a page.
I tried to let a blank here and create a page where I added article module. It’s ok cause it takes in consideration the fact I don’t want a header but if I go on an article the header will appear.

I looked on the forum and found this article:
https://kriesi.at/support/topic/blog-header-displays-when-set-not-too/

.title_container { display: none!important; }

Tried the css in it, refresh and everything,but it’s not working for me. The header is still appearing.

How can I fix this?

Kind regards

Delphine