[b3lm0nt]

First point: the groff file in my gist is designed for plain-text files, so not all the functionality will exactly translate to PDF rendering.

Second point: to resolve the issue you're running into, remove these lines from the groff file to allow the default margins for PDF rendering to occur.

    \# Set the line lenth to \nl
    .ll \nl

There can occasionally be some strange behavior with the macros when different output devices are used (some options are ignored, some may have unexpected consequences). I took a look at the PDF output using my file directly, and it looks like the em sizing for gropdf is different from the grotty implementation, causing some overflow. (Maybe the font needs to be set explicitly before setting the line-length? Not sure).

Using a different unit of measurement (like inches or points) may be a better option for PDF files: https://www.gnu.org/software/groff/manual/html_node/Measurem...

Bonus note: you can confirm the final output device that will be used by a groff command by adding the -V option. Example:

    groff -Tpdf -V examaple.groff

Outputs:

    troff -Tpdf example.groff | gropdf

Using -Tascii instead will produce:

    troff -Tascii example.groff | grotty

Ref on output devices: https://www.gnu.org/software/groff/manual/html_node/Output-D...

* Edit: See 2b3a51's response for a better explanation.