JSFiddle - React, Tailwind, and code Playground

HTML

<div class='line left'></div>
<h1>Hello World</h1>
<div class='line right'></div>

CSS

.line {
    background: black;
    height: 5px;
    display: inline-block;
}

h1 {
    margin-left: 5px;
    margin-right: 5px;
    display: inline;
}

.left {
    width: 25px;
}

.right {
    /* I want this to stretch the remainder */
}