JSFiddle - React, Tailwind, and code Playground

HTML

<fieldset>
    <legend>Legend</legend>
    Content of Fieldset
</fieldset>

CSS

fieldset {
    border:0;
    outline: 1px solid gray;
}

legend {
    font-weight:bold;
    background: orange;
    width: 100%;
    
    -moz-box-sizing: border-box;
    -webkit-box-sizing: border-box;
    box-sizing: border-box;
}