JSFiddle - React, Tailwind, and code Playground

HTML

<div class="layout">
    <div class="sidebar left">
        <div class="sidebar__inner">
            <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Odit delectus odio pariatur nam consectetur aliquid omnis facere blanditiis nulla ex dolorem minus veniam ipsum voluptas autem voluptates adipisci. Maxime debitis!</p>
        </div>
    </div>
    
    <div class="sidebar left">
        <div class="sidebar__inner">
            <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Odit delectus odio pariatur nam consectetur aliquid omnis facere blanditiis nulla ex dolorem minus veniam ipsum voluptas autem voluptates adipisci. Maxime debitis!</p>
        </div>
    </div>
    
    <div class="main">
        <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Repellat sed velit vero quam molestias minus quisquam dicta nihil unde corporis officiis ipsa nostrum. Ipsam enim a accusantium doloremque porro corporis.</p>
        <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Repellat sed velit vero quam molestias minus quisquam dicta nihil unde corporis officiis ipsa nostrum. Ipsam enim a accusantium doloremque porro corporis.</p>
        <p>Lorem ipsum dolor sit amet, consectetur adipisicing elit. Repellat sed velit vero quam molestias minus quisquam dicta nihil unde corporis officiis ipsa nostrum. Ipsam enim a accusantium doloremque porro corporis.</p>
    </div>
</div>

CSS

html, body {
    margin: 0;
    padding: 0;
}
body {
    position: relative;
}

.layout {}
.layout:after {
    clear: both;
    
    content: '';
}

.sidebar {
    position: absolute;
    top: 0;
}
.sidebar.left {
    left: 0;
    right: 50%;
}
.sidebar.left .sidebar__inner {
    margin-right: 480px;

    background: green;
}
.sidebar.right {
    right: 0;
    left: 50%;
}
.sidebar.right .sidebar__inner {
    margin-left: 480px;
    
    background: red;
}
.main {
    width: 960px;
    margin: 0 auto;
}