JSFiddle - React, Tailwind, and code Playground

HTML

<!-- Learn about this code on MDN: https://developer.mozilla.org/en-US/docs/Web/CSS/::-webkit-scrollbar -->

<div class="visible-scrollbar">Thisisaveeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeerylongword</div>
<div class="invisible-scrollbar">Thisisaveeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeerylongword</div>
<div class="mostly-customized-scrollbar">Thisisaveeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeerylongword<br>
And pretty tall<br>
thing with weird scrollbars.<br>
Who thought scrollbars could be made weeeeird?</div>

CSS

.visible-scrollbar, .invisible-scrollbar, .mostly-customized-scrollbar {
  display: block;
  width: 10em;
  overflow: auto;
  height: 2em;
}
.invisible-scrollbar::-webkit-scrollbar {
  display: none;
}

/* Demonstrate a "mostly customized" scrollbar
 * (won't be visible otherwise if width/height is specified) */
.mostly-customized-scrollbar::-webkit-scrollbar {
  width: 5px;
  height: 8px;
  background-color: #aaa; /* or add it to the track */
}
/* Add a thumb */
.mostly-customized-scrollbar::-webkit-scrollbar-thumb {
    background: #000; 
}