css3加载中loading三点依次闪动效果代码

html如何css3加载中loading三点依次闪动加载效果，下面编程教程网小编给大家简单介绍一下实现代码！

html代码：

<div class="loading"></div>

css动态效果代码：

body{
  display: flex;
  align-items: center;
  justify-content: center;
  height: 100vh;
  background: #69a7f7;
}
.loading:before,
.loading:after,
.loading {
  border-radius: 50%;
  width: 2.5em;
  height: 2.5em;
  -webkit-animation-fill-mode: both;
  animation-fill-mode: both;
  -webkit-animation: load7 1.8s infinite ease-in-out;
  animation: load7 1.8s infinite ease-in-out;
}
.loading {
  margin: 8em auto;
  font-size: 10px;
  position: relative;
  text-indent: -9999em;
  -webkit-animation-delay: -0.16s;
  animation-delay: -0.16s;
}
.loading:before {
  left: -3.5em;
  -webkit-animation-delay: -0.32s;
  animation-delay: -0.32s;
}
.loading:after {
  left: 3.5em;
}
.loading:before,
.loading:after {
  content: '';
  position: absolute;
  top: 0;
}
@-webkit-keyframes load7 {
  0%,
  80%,
  100% {
    box-shadow: 0 2.5em 0 -1.3em #ffffff;
  }
  40% {
    box-shadow: 0 2.5em 0 0 #FFF;
  }
}
@keyframes load7 {
  0%,
  80%,
  100% {
    box-shadow: 0 2.5em 0 -1.3em #ffffff;
  }
  40% {
    box-shadow: 0 2.5em 0 0 #FFF;
  }
}