JSFiddle - React, Tailwind, and code Playground

HTML

<script src="https://ajax.googleapis.com/ajax/libs/jqueryui/1.11.4/jquery-ui.min.js"></script>
<link rel="stylesheet" href="https://ajax.googleapis.com/ajax/libs/jqueryui/1.11.4/themes/smoothness/jquery-ui.css">
    <div class="panelgroup">
        <div class="panelheadbar pgrau">Test</div>
        <div class="panelcontent">
            Test<br />
            Test<br />
            Test<br />
            Test<br />
            Test<br />
            Test<br />
            Test<br />
        </div>
    </div>

CSS

.panelheadbar { 
      padding: 5px;
      font-weight: bold;
      color: #000;
      overflow: hidden;
      height: auto;
      cursor: move;
      border-bottom: 1px solid #333>;
}

.pgrau { 
      background-color: #ccc;
}

.panelcontent {
      overflow: auto;
      overflow-x: hidden;
      padding: 10px;
      top: 0px;
      left: 0px;
      background-color: #FFF;
      border-left: 1px solid #333;
      border-right: 1px solid #333;
      border-bottom: 1px solid #333;
}
.ui-resizable-s {
    bottom:0px;   
}

JavaScript

$( ".panelcontent" ).resizable({
    handles: "s"
});