JSFiddle - React, Tailwind, and code Playground

HTML

<div class="header">
    <div class="big">BIG</div>
    <div class="small">SMALL</div>
</div>

CSS

.header {
    overflow: hidden;
    width: 200px;
}
.big {
    float: left;    
    text-decoration: underline;
    font-size: 40px;
}
.small {
    float: right;
    text-decoration: underline;
    font-size: 12px;
}