A book would become absolutist, like the bible. We don’t need an absolutist screed.
No, the beauty is that, unlike the bible, it can be amended along with knowledge and new philosophical insights.
By necessity it would not be possible to be absolute (as is the bible). Do you consider the Constitution and B.O.R. as absolute? We have already amended it several times and we call it “a work in progress”. But it is the law of the land and theoretically, if you act against someone’s constitutional rights you can be sued for satisfaction.
But you cannot kill a person (an eye for an eye) or issue a fatwa (contract) to extract satisfaction. That is an absolute no.
But I am not speaking of a communist carrying his little red book. I see a moral guide based on secular humanist values, which can be taught in school to introduce a secular humanistic view of the world, rather than the Sunday religious indoctrinations of what God has told the preacher on the previous Saturday night (while having a glass of wine).
As there are Universal constants and functions that have produced our world, so do I believe there are secular humanist constants which (in principle) can produce a peaceful world.
Compilation and distribution in book form (essential to people without access to computes) is the real problem. But you can find a bible almost everywhere around the world. Theists had 2000 years to accomplish that considerable feat.