Border-bottom not working, can you put custom css during generation ?

[JonathanCabezas]

I have a live preview of a bill I use to export a pdf.
My border-bottom isn't placed correctly:

I think I've seen somewhere that this is not supposed by jsPDF. I'm really surprised as it doesn't look like a complicated feature, but if that's the case, is there a workaround ?

I added a padding to get the placement correct, but now my live preview is wrong. Can i apply the custom css only during generation, so that it is not visible to the user ?

Thank you in advance :)