JSFiddle - React, Tailwind, and code Playground

HTML

<div class="box">
    <div class="box-head">123</div>
    <div class="box-content">123</div>
</div>

CSS

body {padding: 8px;}
        
        .box {
            margin:15px;
            background: blue;
            position:relative;
            z-index:9999;
            border:1px solid #666;
            border-radius:7px;
        }
        
        .box-head {
            position:relative;
            padding:5px 10px;
            border-top-left-radius: 5px;
            border-top-right-radius: 5px;
            
            background-color: #ffba00;
            background-image: -webkit-gradient(linear, 0 0, 0 100%, color-stop(.5, #ffd800), to(#ffba00)); 
            background-image: -webkit-linear-gradient(#ffd800 0, #ffba00 100%, #ffba00);
            background-image: -moz-linear-gradient(#ffd800 0, #ffba00 100%, #ffba00);    
            background-image: -ms-linear-gradient(#ffd800 0, #ffba00 100%, #ffba00);    
            background-image: -o-linear-gradient(#ffd800 0, #ffba00 100%, #ffba00);    
            background-image: linear-gradient(#ffd800 0, #ffba00 100%, #ffba00);    
    
        }
        
        .box-content {
            background:#edecde;
            padding:15px 10px 10px;
            border-bottom-left-radius: 5px;
            border-bottom-right-radius: 5px;
        }
        
        .box-head:before {
            content:'';
            position:absolute;
            top:100%;left:25px;
            
            width: 0;height: 0;
            border-left: 10px solid transparent;
            border-right: 10px solid transparent;
            border-top: 10px solid #ffba00;
        }
        
        .box:before {
            content:'';
            position:absolute;
            top:-15px;left:-15px;right:-15px;bottom:-15px;
            
            padding:10px;
            border: 2px solid #004c3b;
            border-radius:7px;
            z-index: -1;

              background:transparent -webkit-gradient(linear, left top, left bottom, from(rgba(77,159,141,.3)), to(rgba(40,73,66,.5)));
              background:transparent...