Broken layout for printing

Hey!

I checked how the layout looks like if you print it using the mac feature to "print to PDF".
And it doesn't look to bad, but menu and header stuff is disturbing.
https://cloudup.com/ct-rjX520xQ

For one of my projects we are thinking about using the theme for our own handbook. We require the ability to print (to PDF) - don't ask ...

I'm happy to contribute the required CSS. Therefore I would like to know what way the maintainer likes it to be implemented: As separate print.css file **or** as media query in the theme.css file

Greetings
derRALF

Start by inspecting the theme's SCSS and previewing a page with the browser's print-to-PDF feature. Identify the rules affecting the menu and header in print output; done means the handbook content prints cleanly without those elements interfering.

Written by the indexing model from the issue text.