JSFiddle - React, Tailwind, and code Playground

HTML

<div class="block">
  Lorem ipsum dolor sit amet, consectetur adipisicing elit. Quo quisquam, a neque et saepe numquam eos voluptate aspernatur rem. Nesciunt consectetur perspiciatis, nisi ipsum, quisquam sit suscipit quia illum officiis.
</div>

CSS

.block {
  animation: block 2s linear forwards;
}

 @keyframes block {
    0% {
        opacity: 0;
    }
    100% {
        opacity: 1;
    }
}