Box Shadow Blur

The blur distance. If you defined a black shadow and a blur of 10px, their would be a 10 pixel blur area where the shadow faded evenly from black to transparent at every extremity.

Value Description
(numeric)e.g. '10' would create a 10 pixel blur at the edge of the element's shadow (Microthemer automatically adds the 'px' unit if a unit isn't specified. Other commonly used units include 'em' and '%'. So you could enter '5%'.)

Themeover CSS Reference

Major new release - Microthemer 5.5