JSFiddle - React, Tailwind, and code Playground

HTML

<div class="el"></div>
<div class="el"></div>
<div class="el"></div>
<div class="el"></div>

CSS

.el {
  width: 30px;
  height: 30px;
  display: inline-block;
  animation: blink 2s linear infinite;
  background: #000;
}

.el:nth-child(1) { animation-delay: 0s; }
.el:nth-child(2) { animation-delay: 0.5s; }
.el:nth-child(3) { animation-delay: 1s; }
.el:nth-child(4) { animation-delay: 1.5s; }

@keyframes blink {
  0%, 20% {
    background: #000;
  }
  10% {
    background: #F00;
  }
}