Box Shadow in CSS

Given a block of size 200 by 200, give it a red shadow shifted down by 15px, to the right by 20px, and blurred by 5px.

Given a block of size 200 by 200, add a green shadow to it, shifted up by 15px, to the right by 20px, and without blur.

Given a block of size 200 by 200. Add to it an inner shadow of black color, without offsets, but with a blur of 5px.

Given a block of size 200 by 200, give it an inner shadow of black, shifted down by 3px and to the right by 4px, with a blur of 3px.

Given a block of size 200 by 200. Add two shadows to it - one at the top, one at the bottom.

Given a block of size 200 by 200. Add four shadows to it so that each is on one side of the block with an offset of 30px and without blur. That is, one shadow is strictly on top, another is strictly on the right, and so on.