Writing your own CSS can be fun but it's usually not the fastest way to create and maintain Templates.
Usually you will want to use external CSS libraries that will make your work easier and allow for a simpler maintenance of your Templates.
Choosing a CSS library
While usually choosing a CSS library is a matter of habits and interests, some may have caveats when it comes to the context of printing/PDF-generation.
Frameworks like Bootstrap for instance have enforced opinions when it comes to print styles and that could end up messing with your whole design.
We recommending using libraries with a lighter touch.
Tools like Tailwind CSS or Tachyons are very good options when it comes to PDFMonkey.
Libraries accessible on a Free account
Since PDFMonkey provides what we call Master Templates, we also made hosted versions of resources we used to build them.
You can use the same resources to build your own templates:
Tailwind CSS v2.0.3
We provide a light version of Tailwind CSS v2.0.3, stripped of any style that doesn't make sense in a printing contexte, like animations or responsive utilities. It weights 165 KB.