JSFiddle - React, Tailwind, and code Playground

HTML

<div class="wrapper">
    <div class="leftcol">
        test
    </div>
    <div class="rightcol">
        test
    </div>
</div>

CSS

.wrapper {
    width: 500px;
    margin: 0 auto;
}
.leftcol {
    float: left;
    width: 49%;
    background-color: lightblue;
    margin-right: .5%;
    margin-left: .5%;
}
.rightcol {
    float: left;
    width: 49%;
    background-color: lightgreen;
    margin-right: .5%;
    margin-left: .5%;
}