JSFiddle - React, Tailwind, and code Playground

HTML

<div class=m>


<div class=l_1>
left_______________________________________________X
</div>

<div class=r_1>
right
</div>


</div>

CSS

.m
{	display: flex;
	flex-wrap: wrap;
}

.l_1
{	background-color: red;
	flex: 1 1 50%;
}

.r_1
{	background-color: yellow;
	flex: 1 1 50%;
}