lightest weight of a font is used when making a PDF from a webpage
I have written up the steps in the last comment here:
- make an HTML file from the provided code
- make a PDF from this HTML file
- see if your result is different from the attached PDF in the forum post
Acrobat DC (CC) 21.0 on Mac OS X Big Sur 11.2.3
Helvetica Neue typeface installed with system: /System/Library/Fonts/HelveticaNeue.ttc
A regular (or even medium) weight of a typeface would be chosen.
The lightest available weight of the typeface is chosen, making the resulting PDF unreadable. PDF attached to forum post is also attached here.