How to export package documentation with css using godoc?

Question

After writing my package I know it is possible to generate an html page with all the documentation provided through comments in my code;

godoc -html github.com/user/package > index.html

But the generated file (index.html) has no css, there is a way to use the same style that is used if we use godoc with the flag -http?

dogoc -http=:6060