Seconded. I went with C# + Playwright. I tried iTextSharp, iText, PDFSharp, and wkhtmltopdf, but they all had limitations. I had good results with Playwright in minutes, outside of tweaking the CSS like you mention.

I documented the process here[0] if anyone needs examples of the CSS and loading web fonts. Apologies for the article being long-winded – it was the first one I published.

[0] https://johnh.co/blog/creating-pdfs-from-html-using-csharp

Thirded, you can build this straight into your backend or into a microservice very easily.

You can also easily generate screenshots if that's more suitable than PDFs.

You can also easily use this to do stuff like jam a set of images into a HTML table and PDF or screenshot them in that format.