blur background image css

.mydiv { filter: grayscale(50%) }

/* Graut alle Bilder um 50% aus und macht sie um 10px unscharf */
img {
  filter: grayscale(0.5) blur(10px);
}

backdrop-filter: blur(5px);

html, body {
  width: 100%;
  height: 100%;
}

.container {
  width: 100%;
  height: 100%;
  
  display: grid;
  grid-template-columns: 1fr 6fr 1fr;
  grid-template-rows: 1fr 6fr 1fr;
  grid-template-areas: 
  '. . .'
  '. content .'
  '. . .'; 
  justify-content: center;
  align-items: center;
}

.backbround {
  width: 100%;
  height: 100%;
  
  grid-area: 1/1/5/5;
  
  background-image: url(https://i.imgur.com/aUhpEz3.jpg);
  filter: blur(5px);
  background-position: center;
  background-repeat: no-repeat;
  background-size: cover;
}

.content {
  height: 200px;
  position: relative;
  
  grid-area: content;
  display: flex;
  
  justify-content: center;
  align-items: center;
  color: white;
}