Property backdrop-filter

Defines a graphical effect to the area behind
an element

To see the effect, the element or its background
must be at least partially transparent.

A space-separated list of filter-functions like:

blur()
brightness()
contrast()
drop-shadow()
grayscale()
hue-rotate()
invert()
opacity()
sepia()
saturate()

or an url to an SVG filter that will be applied
to the backdrop