add base64 decoding for css source
add base64 decoding for css source

fateevv/basisjs,tyanas/basisjs,istrel/basisjs,tyanas/basisjs,fateevv/basisjs,smelukov/basisjs,smelukov/basisjs,basisjs/basisjs,tyanas/basisjs,basisjs/basisjs,fateevv/basisjs,istrel/basisjs,basisjs/basisjs,smelukov/basisjs,istrel/basisjs