                        課程
                    
                        /前端開發
                        
                            /HTML/CSS
                        
                        /HTML5小游戲---愛心魚（上）

求助！畫布無法在適應在瀏覽器正中間

<!DOCTYPE?html>
<html>
<head>
<meta?charset="utf-8">
????<title>tinyHeart</title>
????<style?type="text/css">
????????body?{
????????????padding-top:10px;
????????}

????????.all_bg{
????????????width:800px;
????????????height:600px;
????????????margin:?0px?auto;
????????}
????????#allconvas{
????????????position:?relative;
????????????width:?800px;
????????????height:?600px;
????????????margin:?0px;
????????}
????????#canvas1{
????????????position:?absolute;
????????????bottom:?0;
????????????left:?0;
????????????z-index:?1;
????????}
????????#canvas2{
????????????position:?absolute;
????????????bottom:?0;
????????????left:?0;
????????????z-index:?0;
????????}
????</style>
</head>
<body>
????<div?calss="all_bg">
????????<div?id="allcanvas">
????????????<canvas?id="canvas1"??width="800"??height="600"></canvas>
????????????<canvas?id="canvas2"??width="800"??height="600"></canvas>
????????</div>
????</div>
????</body>
</html>

一直顯示在瀏覽器左下角，而且ui設置應該是畫布正中才對，顯示卻偏右..