I can't. This template is used only to render a PDF. And it was impossible to use the "standard" stylesheets block. 

Real problem is I can't use this https://github.com/KnpLabs/#render-a-pdf-document-with-a-relative-url-inside-like-css-files as the process always crashes (timeout). So I have to use this method, https://github.com/KnpLabs/#render-a-pdf-document-as-response-from-a-controller and insert only the CSS I need.