back background image effect css code example
Example 1: php code to display a div with background fade
body {
background: url('http://placehold.it/1600x1200') no-repeat center center fixed;
-webkit-background-size: cover;
-moz-background-size: cover;
-o-background-size: cover;
background-size: cover;
}
Example 2: css backdrop filter grayscale
backdrop-filter: grayscale(30%);