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;
}
pre code {
  color: #fff;
  background-color: #aaa;
  border: 1px solid #999;
  display: block;
  padding: 5px;
  overflow-x: auto;
  white-space: pre-wrap;
  white-space: -moz-pre-wrap;
  white-space: -pre-wrap;
  white-space: -o-pre-wrap;
  word-wrap: break-word;
}