https://animate.style/

默认循环动画：
<h1 style="font-size:50px;color:red" class="animated fadeOutUp infinite">+1</h1>
infinite

+1

缓慢循环动画：
<h1 style="font-size:50px;color:red" class="animated fadeOutUp infinite slower">+1</h1>
slow|slower|fast|faster

+1

https://cssanimation.io/index.html

<style>
.hu__hu__ { animation: hu__hu__ infinite 2s ease-in-out }
@keyframes hu__hu__ {
    50% { transform: translateY(30px) }
}
</style>
<div class="cssanimation hu__hu__"> Quicker </div>