the background-image make it full in the screen code example
Example 1: html background image fit to screen
body {
background-position: center;
background-repeat: no-repeat;
background-size: contain;
}
Example 2: bootstrap create full screen background image
.wrapper{background: url('/assets/64531/green_suburb.jpg') no-repeat center center fixed;
-webkit-background-size: cover;
-moz-background-size: cover;
-o-background-size: cover;
background-size: cover;}