Fit-one-screen maths belongs to each look

The block is small and looks shareable: measure the header, the hero frame and the info column, then gap = (screenHeight − header − hero − info − minimum) / 2, floored at minimum, drawn above and below the hero so it lands optically centred with the rest just reaching the fold.

// adapted
LaunchedEffect(headerDp, heroDp, infoDp, screenInfo, minimumDp) {
    if (headerDp > 0 && heroDp > 0 && infoDp > 0 && screenInfo.hDP > 0) {
        val result = (screenInfo.hDP - headerDp - heroDp - infoDp - minimumDp) / 2
        gapDp = if (result > minimumDp) result else minimumDp
    }
}

Traps