JSFiddle - React, Tailwind, and code Playground

HTML

<style>
.header {
    float:left;
    width:50%;
    border:1px solid black;
    margin:0 -1px;
}
</style>

<div style="width:100%;">
    <div class="header">Hello</div>
    <div class="header">World</div> 
</div>