background imagesize:800x800 code example
Example 1: css background image cover center
html {
background: url(images/bg.jpg) no-repeat center center fixed;
-webkit-background-size: cover;
-moz-background-size: cover;
-o-background-size: cover;
background-size: cover;
}
Example 2: how to scale a bg image acc to size of div
/* One way */
background-size: cover;
/* Other option */
background-size: contain;