The wrapper that pads content below the fixed header lacked min-h-0, so as a
flex child with min-height:auto it grew to its content's height instead of
staying bounded to the viewport. That let the whole document scroll (the fixed
header/nav stayed put while content ran off-screen). Add min-h-0 so the wrapper
stays viewport-height and the inner <main> keeps its own overflow scroll.
peter
076a2fbe6f