html {
  background: url("https://img4.goodfon.com/wallpaper/nbig/2/39/tokho-toukhou-devushka-fon-mech.jpg") no-repeat center center fixed;
  -webkit-background-size: cover;
  -moz-background-size: cover;
  -o-background-size: cover;
  background-size: cover;
}
.card {
    opacity: 0.9;
}
.blurry {
  backdrop-filter: blur(7px) !important;
  box-shadow: 0 1px 3px rgba(0,0,0,0.12), 0 1px 2px 
}