JSFiddle - React, Tailwind, and code Playground

HTML

<h1>Heading</h1>
<h1>This is a longer heading</h1>

CSS

h1 {
    overflow: hidden;
    text-align: center;
}
h1:before,
h1:after {
    background-color: #000;
    content: "";
    display: inline-block;
    height: 1px;
    position: relative;
    vertical-align: middle;
    width: 50%;
}
h1:before {
    right: 0.5em;
    margin-left: -50%;
}
h1:after {
    left: 0.5em;
    margin-right: -50%;
}