JSFiddle - React, Tailwind, and code Playground

HTML

<div class="preloader__progress">
  <div id="progressBar" class="preloader__progress-bar"></div>
</div>

CSS

.preloader__progress {
  position: relative;
  overflow: hidden;
  height: 40px;
  width: 996px;
  max-width: 90%;
  margin: auto;
  border: 2px solid #fff;
}

.preloader__progress-bar {
  position: absolute;
  top: 0;
  left: 0;
  height: 100%;
  width: 100%;
  background-color: #fff;
}