Negative Values of Box Shadow

Question

Negative values are not allowed for -
1.horizontal offset
2.vertical offset
3.blur radius
4.spread radius

Answer 1

The horizontal offset of the shadow, positive means the shadow will be on the right of the box, a negative offset will put the shadow on the left of the box.
The vertical offset of the shadow, a negative one means the box-shadow will be above the box, a positive one means the shadow will be below the box.
The blur radius , if set to 0 the shadow will be sharp, the higher the number, the more blurred it will be.
The spread radius , positive values increase the size of the shadow, negative values decrease the size. Default is 0.