html {  
        margin:0; 
        padding:0; 
        background: url(images/bg.png) no-repeat center center fixed;  
        -webkit-background-size: 100%
        -moz-background-size: 100%
        -o-background-size: 100%
        background-size: 100%
        } 
		    
	div{
     width:100%;
     height:100vh;
     position:relative;
    }
    canvas{
     position:absolute;
     top:0;bottom:0;right:0;left:0;
     margin:auto;
    }