JSFiddle - React, Tailwind, and code Playground

HTML

<div class="header-wrap">
    <div class="header">header</div>
</div>
<div class="content-wrap">
    <div class="content">content</div>
</div>

CSS

.header-wrap {
    background-color:yellow;
    display:inline-block;
}
.content-wrap {
    background-color:orange;
}
.header {
    margin:0 auto 1em auto;
    background-color: red;
    width:40em;
}