.dv { background-color: pink; height: 160px; width: 100px; border-radius: 10px; animation-name: identifier; //动画时长 animation-duration: 1.2s; //动画速度曲线 ease 默认，linear，ease-in，ease-out，ease-in-out，cubic-bezier(n,n,n,n) n:0-1 animation-timing-function: ease-in; //播放次数 n，infinite animation-iteration-count: infinite; //是否反向播放 normal，alternate animation-direction: alternate; } @keyframes identifier{ 0% { height: 160px; } 100% { height: 0px; } }