A typographic lighting effect
This property casts a drop shadow across text using a light source from a specified direction and distance.
This property expects four values: offset-x, offset-y, blur-radius, and color. The first two values are required. Blur-radius and color are optional.
Positive values for offset-x and offset-y define a light source above and to the left, casting a shadow below and to the right. Negative values have the opposite effect.
Larger blur-radius values create a wider and more diffuse light scatter.
More than one shadow may be specified by separating each group of four values with commas.