JSFiddle - React, Tailwind, and code Playground

HTML

<div class="post-date"><p>13.09</p></div>

CSS

html, body{
    margin:0;
    padding:0;
}
body{
    width:280px;
    min-height:250px;
    padding-top:50px;
    padding-left:10px;
    padding-right:10px;
    font-size:12px;
    font-family:"Arial", sans-serif;
    line-height:1.2;
    color:#7f8c8d;
    background:#ecf0f1;
}
.post-date{
    width:50px;
    height:45px;
    background:white;
    font-size:15px;
    font-weight:bold;
    border-bottom:5px solid #bdc3c7;
    text-align:center;
}
.post-date p {
    display: inline-block;
    vertical-align: middle;
}