html {height: 100%;}
body {background-color: lightcyan; height: 90%;}
div.main
{
  background-color: rgba(255, 255, 255, 0.25);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  border: 1px solid rgba(255, 255, 255, 0.18);
  box-shadow: rgba(142, 142, 142, 0.19) 0px 6px 15px 0px;
  -webkit-box-shadow: rgba(142, 142, 142, 0.19) 0px 6px 15px 0px;
  border-radius: 5px;
  -webkit-border-radius: 5px;
  color: rgba(0, 0, 0, 0.75);
  height: 80%; width: 80%;
  margin: auto; margin-top: 70px;
}