.canvasLayer {
            width: 640px;
            max-width: 100%;
            position: relative;
            padding: 0;
            box-sizing: content-box;
}
.canvasLayer:before{
            content:"";
            display: block;
            padding-top: 100%;
}
.canvas{
            position: absolute;
            left:0;
            top:0;
            border: 0;
            max-width:100%;
            box-sizing: content-box;
            padding: 0;
            margin: 0;
}