Even 80 characters could be too long for some screens / font size. Long lines could be broken (like white-space: pre-wrap does), with an indicator that the line

Even 80 characters could be too long for some screens / font size. Long lines could be broken (like white-space: pre-wrap does), with an indicator that the line has been broken at the beginning of the continued lines. This is what Kate does and I think it is a good default, better than having to scroll horizontally.