Integration with Success Factors and styling is not being complied to?

We have Success Factors Recruiting and have used the standard API to connect to Docusign for e-signing the offer letters, work contracts etc

The SF editor is quite poor and despite my efforts to date I cannot get the ‘ok in SF preview’ to be the same in Docusign. I have tried explicit inline CSS, using tables and using CoPilot to help me with variations of simple HTML that is then rendered correctly in Docusign. The Text is too large on the whole when it gets to Docusign.
The issue I think is that the SF end is HTML that Docusign tries to convert to a PDF - we use ‘tokens’ or preset field variables in the SF side to populate fields like name date etc.

Would be very appreciative of anyone who has navigated this issue or can help with guidance on further steps to try

thanks

Darren