JSFiddle - React, Tailwind, and code Playground

HTML

<div class="parent">
    <div class="scrollContainer" id="trbx">
      <div class="innerScroll">
            Lots of text goes here. Lots of text goes here. Lots of text goes here.
            Lots of text goes here. Lots of text goes here. Lots of text goes here.
            Lots of text goes here. Lots of text goes here. Lots of text goes here.
            Lots of text goes here. Lots of text goes here. Lots of text goes here.
            Lots of text goes here. Lots of text goes here. Lots of text goes here.
            Lots of text goes here. Lots of text goes here. Lots of text goes here.
            Lots of text goes here. Lots of text goes here. Lots of text goes here.
            Lots of text goes here. Lots of text goes here. Lots of text goes here.
            Lots of text goes here. Lots of text goes here. Lots of text goes here.
            Lots of text goes here. Lots of text goes here. Lots of text goes here.
            Lots of text goes here. Lots of text goes here. Lots of text goes here.
            Lots of text goes here. Lots of text goes here. Lots of text goes here.
            Lots of text goes here. Lots of text goes here. Lots of text goes here.
            Lots of text goes here. Lots of text goes here. Lots of text goes here.
            Lots of text goes here. Lots of text goes here. Lots of text goes here.
            Lots of text goes here. Lots of text goes here. Lots of text goes here.
            Lots of text goes here. Lots of text goes here. Lots of text goes here.
            Lots of text goes here. Lots of text goes here. Lots of text goes here.
            Lots of text goes here. Lots of text goes here. Lots of text goes here.
            Lots of text goes here. Lots of text goes here. Lots of text goes here.
            Lots of text goes here. Lots of text goes here. Lots of text goes here.
            Lots of text goes here. Lots of text goes here. Lots of text goes here.
            Lots of text goes here. Lots of text...

CSS

.parent
{
    margin:0px;
    padding:0px;
	height: 400px;
	background-color: #808080;
	border: none;
}

#trbx
{    
    width:100%;
    height:100%;
    margin:0px;
}

.scrollContainer
{
    margin: 0px;
	  position: relative;
	  border: none;
    bottom:0px;
    top:0px;
    left:0px;
    right: 0px;
    height:100%;
}

.innerScroll
{
	overflow-y: auto;
	position: absolute;
	top: 0px;
	bottom: 0px;
	left: 0px;
	right: 0px;
}