Apple announced the iPhone Duo, its first foldable, on September 10th. Most of the coverage is about the hinge and the $1,999 price tag. I want to talk about something narrower: what the two displays actually measure, and what that does to CSS you have already written. Short version: Folded and unfolded, both displays sit at roughly 1 : 1.42 . Not 9 : 19.5. Not close to it. Logical resolution works out to about 466 x 678pt folded and 890 x 626pt unfolded . The web standard for fo...