<style>
        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: 1s;
            /*此处写代码*/
            animation:disp 1s linear 2s infinite;
           
       }
       @keyframes disp{
           0%{
               /* top:-1000px; */
               transform: translateY(-1000px);
           }
           50%{
               /* top:0; */
               transform: translateY(1000px);
           }
           100%{
               /* top:0; */
               transform: translateY(1000px);
           }
       }
    </style>
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