JSFiddle - React, Tailwind, and code Playground

HTML

<div>
  <h1><strong>Wie bekomme ich das hin?</strong></h1>
</div>

CSS

div { 
        line-height: 1.2; 
        padding: 0; 
        /*border-left: 2em solid #c0c; */
        display:inline-block; 
        width: 300px;
    }
    h1 { 
        background-color: #F00; 
        color: #fff; 
        display: inline; 
        margin: 0; 
        padding: 0 10px 0 0;
        line-height: 44px;
        font-size: 35px;
    } 
    h1 strong { 
        position: relative; 
        left: 5px;
    }