body {
    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background-color: #f4f6f9;
	
	/* Set up your background image source */
  /*  background-image: url('file:///http://ptess.edu.tt/ptess.png');*/
	background-image: linear-gradient(rgba(255, 255, 255, 0.5), rgba(255, 255, 255, 0.5)), url('http://ptess.edu.tt/ptess.png');
    
    /* Prevents the image from tiling */
    background-repeat: no-repeat;
    
	 /* Unfreezes background for older mobile browsers to prevent performance stuttering */
    background-attachment: scroll; 
	
	/* Shrinks the entire image width to fit 100% of the mobile screen */
    background-size: 100% auto; 
    
    /* Centers the main focus of the image on narrow vertical screens */
    background-position: center 10px; 
}