Generate PDF from selector in current page with CSS

I would like to know how to generate a PDF from a selector that I define and that all the formatting of this selector comes correctly in the PDF?

I want to make client-server. Example: Imagine that I have a full page, hence I have a specific area that has a graphic, I want to generate a PDF, but the content of the PDF will be just the one of the graphic. You can take as an example the printElement that printed an element. What I want is this:

$( '#minhaDiv' ).gerarPDF();

It also serves as a file, it does not have to be exactly what I have on the current page, but as long as CSS is not omitted at generation time.