JSFiddle - React, Tailwind, and code Playground

HTML

<div class="x a"></div>
<div class="x b"></div>
<div class="x c"></div>

CSS

.x {
  width: 15px;
  height: 15px;
  background: #dbdbdb;
  border-radius: 50px;
  display: inline-block;
  animation: fade 1s forwards;
  -webkit-animation: fade 1s forwards;
  -moz-animation: fade 1s forwards;
  -o-animation: fade 1s forwards;
  animation-iteration-count: infinite;
  -webkit-animation-iteration-count: infinite;
  -moz-animation-iteration-count: infinite;  
  -o-animation-iteration-count: infinite;
}


.b 
{
    animation: fade 2s forwards;
  -webkit-animation: fade 2s forwards;
  -moz-animation: fade 2s forwards;
  -o-animation: fade 2s forwards;
  animation-iteration-count: infinite;
  -webkit-animation-iteration-count: infinite;
  -moz-animation-iteration-count: infinite;  
  -o-animation-iteration-count: infinite;
}
.c 
{
    animation: fade 3s forwards;
  -webkit-animation: fade 3s forwards;
  -moz-animation: fade 3s forwards;
  -o-animation: fade 3s forwards;
  animation-iteration-count: infinite;
  -webkit-animation-iteration-count: infinite;
  -moz-animation-iteration-count: infinite;  
  -o-animation-iteration-count: infinite;
}

@keyframes fade {
0%   {opacity:0;}
50%   {opacity:1;}
100% {opacity:0;}
}

@-webkit-keyframes fade {
0%   {opacity:0;}
50%   {opacity:1;}
100% {opacity:0;}
}

@-moz-keyframes fade {
0%   {opacity:0;}
50%   {opacity:1;}
100% {opacity:0;}
}

@-o-keyframes fade {
0%   {opacity:0;}
50%   {opacity:1;}
100% {opacity:0;}
}