Separator line

3 The black line between the two sides of Split View can be dragged left or right to change the amount of space allocated to each app. Put the pointer over the line and it will change to an arrow – double-headed when you can drag either way, and single-headed when the app on one side can be shrunk no further. The apps will redraw their contents to make the best use of the available space. You can double-click the line to split the screen evenly.