JSFiddle - React, Tailwind, and code Playground

HTML

<div class="cb">
        
    <div class="cb x">
    text<br>
    text<br>
    text<br>
    text<br>
    text<br>
    text<br>
    text<br>
    text<br>			    
   </div>
        
</div>

CSS

.cb {
	width: 340px;
	height: 331px;
	border: 1px solid #ccc;
	padding: 0;
	background: #ccc;
	color: #fff;
	position: fixed;
	bottom: 0;
	right: 41px;
}

.cb .x {
    top:231px;
    left:0;
    position:relative;
	width: -webkit-calc(100% - 18px);
    width: calc(100% - 18px);
	height: 100px;
	border: 0;
	padding: 10px;
	background: #781111;
	overflow-y: auto;
}