JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>task2</title>
<link href="style.css" rel="stylesheet" type="text/css">
</head>
<style>
    body{margin:25px;}
.wrap {
    background: #c9e39c;
    position:relative;
    padding: 10px 13px;
}
.title {
    background: #c9e39c;   
    height: 30px;
    padding: 0 10px;
    font: bold 14px/30px Arial, Helvetica, sans-serif;
    position: relative;
    max-width: 250px;
        
}
.title h1{width:auto;}
.title:before, .wrap:before {
    content: "";
    position: absolute;
    z-index: -1;
    border: 1px solid #a3d869; 
    box-shadow: 0 0 4px #999;
    -webkit-box-shadow: 0 0 4px #999;
    -moz-box-shadow: 0 0 4px #999;
}
.cor3:before {
    top: 0;
    bottom: 0px;
    right: 0;
    left: 0;
    
}
.cor4:before {
    top: 0px;
    bottom: 0px;
    right: 0px;
    left: 0px;
}
</style>
<body>


<div class="title cor3"><h1>Заголовок</h1></div>
<div class="wrap cor4">Содержание блока</div>

</body>
</html>