JSFiddle - React, Tailwind, and code Playground

HTML

<!DOCTYPE html>
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>Эскиз</title>



</head>

<body>

<div class="block1">
    <div class="gborder">
        <div class="vborder">
            <div class="content">Рабочий эскиз</div>
        </div>
    </div>
</div>

</body>
</html>

CSS

.block1 {
    float: left; 
    width: 100%;
    }

.gborder {
    margin: 15px 0;
    padding: 0 15px;
    
    border: 1px solid #666;
    border-width: 1px 0;    
    }

.vborder {
    margin: -16px 0 -14px;
    padding: 16px 0 14px;
    
    border: 1px solid #666;
    border-width: 0 1px;    
    }

.content {
    padding: 10px;
    background: #f0f0f0;
    line-height: 1.25em;
    }