Edit in JSFiddle

    var background_a;
    var background_b;
    var twidth;
    var theight;
    var xscale;
    var yscale;
    var rec;
    var rec2;
    var height = $(window).height();
    var width = $(window).width();


    window.onload = function () {
    
        var paper = Raphael(0,0,"100%","100%");
        xscale=1;
        yscale=1;
        twidth = $(window).width();
        theight = $(window).height();
        background_a = paper.rect(0,0,twidth,theight)
        .attr({
            stroke:"none",
            fill:"45-#f00-#808"
        });
        
        rec = paper.rect("20%","20%","30%","30%")
            .attr({fill:"#fff",opacity:0.8,stroke:"none"});
        rec2 = paper.rect("20%","60%","30%","30%")
            .attr({fill:"#fff",opacity:0.8,stroke:"none"});
        rec3 = paper.rect("60%","20%","30%","30%")
            .attr({fill:"#fff",opacity:0.8,stroke:"none"});
        rec4 = paper.rect("60%","60%","30%","30%")
            .attr({fill:"#fff",opacity:0.8,stroke:"none"});
        rec5 = paper.rect("40%","40%","10%","10%")
            .attr({fill:"#fff",opacity:0.6,stroke:"none"});
        rec6 = paper.rect("60%","40%","10%","10%")
            .attr({fill:"#fff",opacity:0.6,stroke:"none"});  
        rec7 = paper.rect("40%","60%","10%","10%")
            .attr({fill:"#fff",opacity:0.6,stroke:"none"});  
        rec8 = paper.rect("60%","60%","10%","10%")
            .attr({fill:"#fff",opacity:0.6,stroke:"none"});
        rec9 = paper.rect("45%","55%","5%","5%")
            .attr({fill:"#fff",opacity:0.4,stroke:"none"});
        rec10 = paper.rect("45%","55%","5%","5%")
            .attr({fill:"#fff",opacity:0.4,stroke:"none"});  
        rec11 = paper.rect("55%","45%","5%","5%")
            .attr({fill:"#fff",opacity:0.4,stroke:"none"});  
        rec12 = paper.rect("55%","55%","5%","5%")
            .attr({fill:"#fff",opacity:0.4,stroke:"none"});        
        
        background_b = paper.rect(0,0,twidth,theight)
        .attr({
            stroke:"none",
            fill:"90-#003-#f00",
            opacity:.1
        });
        
        background_b.mousemove(back_mousemoved);

        function back_mousemoved(e){
            rec.attr({x:getX(20,e.x,4) +"%",
                      y:getY(20,e.y,4) +"%"});
            rec2.attr({x:getX(20,e.x,4) +"%",
                      y:getY(60,e.y,4) +"%"});
            rec3.attr({x:getX(60,e.x,4) +"%",
                      y:getY(20,e.y,4) +"%"});
            rec4.attr({x:getX(60,e.x,4) +"%",
                      y:getY(60,e.y,4) +"%"});
            rec5.attr({x:getX(40,e.x,6) +"%",
                      y:getY(40,e.y,6) +"%"});
            rec6.attr({x:getX(40,e.x,6) +"%",
                      y:getY(60,e.y,6) +"%"});  
            rec7.attr({x:getX(60,e.x,6) +"%",
                      y:getY(40,e.y,6) +"%"});  
            rec8.attr({x:getX(60,e.x,6) +"%",
                      y:getY(60,e.y,6) +"%"});
            rec9.attr({x:getX(45,e.x,9) +"%",
                      y:getY(45,e.y,9) +"%"});
            rec10.attr({x:getX(45,e.x,9) +"%",
                      y:getY(55,e.y,9) +"%"});  
            rec11.attr({x:getX(55,e.x,9) +"%",
                      y:getY(45,e.y,9) +"%"});  
            rec12.attr({x:getX(55,e.x,9) +"%",
                      y:getY(55,e.y,9) +"%"});             
        }
        
        function getX(ox,x,z){
            return ox - (x/width*100)/z;
        }
        function getY(oy,y,z){
            return oy - (y/height*100)/z;
        }
        
        
    };



    window.onresize = function () {
        
        var w = $(window).width();
        var h = $(window).height();
        xscale = w/twidth;
        yscale = h/theight;
        twidth = w;
        theight = h;
        draw();
        
    }
    
    //背景のリサイズ                        
    function draw(){
        background_a.scale(xscale,yscale,0,0);
        background_b.scale(xscale,yscale,0,0);
    }

<script type="text/javascript" src="http://dl.dropbox.com/u/63305355/raphael-min.js"></script>
<div id="canvas">

</div>

body,html
{
    height:100%;
    margin:0;
}

#canvas 
{
    height:99%;
    background:#000;
    text-align:center;
}

.text{
    letter-spacing: 20px;
    color:#fff;
    font-size:150%;
    width:60%;
    height:60%;
    position:absolute;
    left:20%;
    top:40%;
    z-index:1;
}