JSFiddle - React, Tailwind, and code Playground

HTML

<div id="chatlist" class="mousescroll gridcontainer">
        <ul>
            <li>Aug 19, 2011 - Here is an update to Stephen P.'s post to have a styled scroll bar.  -Mike ... You set the overflow to none normally and ...</li>
            <li>Aug 19, 2011 - Here is an update to Stephen P.'s post to have a styled scroll bar.  -Mike ... You set the overflow to none normally and ...</li>
            <li>Aug 19, 2011 - Here is an update to Stephen P.'s post to have a styled scroll bar.  -Mike ... You set the overflow to none normally and ...</li>
            <li>Aug 19, 2011 - Here is an update to Stephen P.'s post to have a styled scroll bar.  -Mike ... You set the overflow to none normally and ...</li>
            <li>Aug 19, 2011 - Here is an update to Stephen P.'s post to have a styled scroll bar.  -Mike ... You set the overflow to none normally and ...</li>
            <li>Aug 19, 2011 - Here is an update to Stephen P.'s post to have a styled scroll bar.  -Mike ... You set the overflow to none normally and ...</li>
            <li>Aug 19, 2011 - Here is an update to Stephen P.'s post to have a styled scroll bar.  -Mike ... You set the overflow to none normally and ...</li>
            <li>Aug 19, 2011 - Here is an update to Stephen P.'s post to have a styled scroll bar.  -Mike ... You set the overflow to none normally and ...</li>
            <li>Aug 19, 2011 - Here is an update to Stephen P.'s post to have a styled scroll bar.  -Mike ... You set the overflow to none normally and ...</li>
            <li>Aug 19, 2011 - Here is an update to Stephen P.'s post to have a styled scroll bar.  -Mike ... You set the overflow to none normally and ...</li>
            <li>Aug 19, 2011 - Here is an update to Stephen P.'s post to have a styled scroll bar.  -Mike ... You set the overflow to none normally and ...</li>
            <li>Aug 19, 2011 - Here is an update to Stephen P.'s post to have a styled scroll bar.  -Mike ... You set the overflow to none normally and...

CSS

#chatlist {
    width: 500px;
    height: 300px;
    border: 1px solid black;
    overflow: hidden;
}
#chatlist ul {
    height: 100%;
    width: 520px;
    overflow-y: scroll;
}