给伪类添加动画，动态显示省略号实现加载中特效，在开发者工具中都正常展示，在手机中color起作用，content修改不起作用，代码如下：

.dot::after {
  width: 40rpx;
  display: inline-block;
  content: "";
  animation: dot 1s infinite;
}

[@keyframes](/user/keyframes) dot {
  0%, 100% {
    content: "";
    color: red;
  }

  25% {
    content: ".";
    color: green;
  }

  50% {
    content: "..";
    color: blue;
  }

  75% {
    content: "...";
    color: pink;
  }
}