Horizontal offset is 20px and vertical offset is 5px.
Positive values of an x-offset mean shadow will be displaced towards the right side along the x-axis
Positive values of a y-offset means shadow will be displaced towards the bottom side along the y-axis
Horizontal offset is -20px and vertical offset is -10px.
Negative values of an x-offset mean shadow will be displaced towards the left side along the x-axis
Negative values of a y-offset means shadow will be displaced towards the top side along the y-axis