viewer(css): adding grayscale & wait cursor while loading (#10305)
viewer(css): adding grayscale & wait cursor while loading (#10305)


ev1stensberg/lighthouse,umaar/lighthouse,umaar/lighthouse,ev1stensberg/lighthouse,GoogleChrome/lighthouse,ev1stensberg/lighthouse,GoogleChrome/lighthouse,GoogleChrome/lighthouse,GoogleChrome/lighthouse,GoogleChrome/lighthouse,ev1stensberg/lighthouse,umaar/lighthouse,umaar/lighthouse