老師有什麼可以改進?

<!DOCTYPE html>
<html>
<head>
    <meta charset="UTF-8">
    <title>2-4</title>
    <style type="text/css">
        div {
            font-family: 'Microsoft Yahei';
            font-size: 60px;
            font-weight: bold;
            line-height: 600px;
            position: absolute;
            top: -1000px;
            right: 0;
            left: 0;
            width: 800px;
            height: 600px;
            margin: auto;
            text-align: center;
            border: 5px solid #000;
            border-radius: 50%;
            animation-name: disp;
            animation-duration: 2s;
            animation-delay: 2s;
            /*此处写代码*/
       }

       @keyframes disp{
        from{top:-1000px;}
        to{top:1000px; }

       }

   </style>
</head>
<body>
    <div>大家好，欢迎来到慕课网！</div>
</body>
</html>

weixin_慕雪0272820 2020-06-22

源自：CSS3动画 2-13 编程练习