使用方法：

1、head引入css文件

<style>
body {
  background-color: #3498DB;
  overflow: hidden;
}

div {
  margin: 175px auto;
}

.drop {
  position: relative;
	width: 20px;
	height: 20px;
  top: -30px;
  margin: 0 auto;
	background: #FFF;
	-moz-border-radius: 20px;
	-webkit-border-radius: 20px;
	border-radius: 20px;
  -moz-animation-name: drip;
  -webkit-animation-name: drip;
  animation-name: drip;
  -moz-animation-timing-function: cubic-bezier(1,0,.91,.19);
  -webkit-animation-timing-function: cubic-bezier(1,0,.91,.19);
  animation-timing-function: cubic-bezier(1,0,.91,.19);
  -moz-animation-duration: 2s;
  -webkit-animation-duration: 2s;
  animation-duration: 2s;
  -moz-animation-iteration-count: infinite;
  -webkit-animation-iteration-count: infinite;
  animation-iteration-count: infinite;
}

.drop:before {
  content: "";
  position: absolute;
  width: 0;
	height: 0;
	border-left: 10px solid transparent;
	border-right: 10px solid transparent;
	border-bottom: 30px solid rgba(255,255,255,1);
  top: -22px;
}

.wave {
  position: relative;
  opacity: 0;
  top: 0;
	width: 2px;
	height: 1px;
  border: #FFF 7px solid;
	-moz-border-radius: 300px / 150px;
	-webkit-border-radius: 300px / 150px;
	border-radius: 300px / 150px;
  -moz-animation-name: ripple;
  -webkit-animation-name: ripple;
  animation-name: ripple;
  -moz-animation-delay: 2s;
  -webkit-animation-delay: 2s;
  animation-delay: 2s;
  -moz-animation-duration: 2s;
  -webkit-animation-duration: 2s;
  animation-duration: 2s;
  -moz-animation-iteration-count: infinite;
  -webkit-animation-iteration-count: infinite;
  animation-iteration-count: infinite;
}

.wave:after {
  content: "";
  position: absolute;
  opacity: 0;
  top: -5px;
  left: -5px;
	width: 2px;
	height: 1px;
  border: #FFF 5px solid;
	-moz-border-radius: 300px / 150px;
	-webkit-border-radius: 300px / 150px;
	border-radius: 300px / 150px;
  -moz-animation-name: ripple-2;
  -webkit-animation-name: ripple-2;
  animation-name: ripple-2;
  -moz-animation-duration: 2s;
  -webkit-animation-duration: 2s;
  animation-duration: 2s;
  -moz-animation-iteration-count: infinite;
  -webkit-animation-iteration-count: infinite;
  animation-iteration-count: infinite;
}

@keyframes ripple {
    from {
      opacity: 1;
    }
    to {
      width: 600px;
      height: 300px;
      border-width: 1px;
      top: -100px;
      opacity: 0;
    }
}

@keyframes ripple-2 {
    0% {
      opacity: 1;
    }
    50% {
      opacity: 0;
    }
  100% {
    width: 200px;
    height: 100px;
    border-width: 1px;
    top: 100px;
    left: 200px;
  }
}

@keyframes drip {
    to {
      top: 190px;
    }
}
</style>

2、body引入HTML代碼

<div class="drop"></div>
<div class="wave"></div>