/* slightly transparent fallback */ .backdrop-blur { background-color: rgba(255, 255, 255, .9); } /* if backdrop support: very transparent and blurred */ @supports ((-webkit-backdrop-filter: blur(2em)) or (backdrop-filter: blur(2em))) { .backdrop-blur { background-color: rgba(255, 255, 255, .5); -webkit-backdrop-filter: blur(2em); backdrop-filter: blur(2em); } }