JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
    <div class="left">
        <div class="content"></div>
    </div>
    <div class="right">
        <div class="content"></div>
    </div>
</div>

CSS

.container {
    width: 100%;
    position: relative;
}

.left {
    position: absolute;
    left: 0;
    top: 0;
}

.left .content {
    width: 200px;
    height: 200px;
    background-color: red;
}

.right {
    padding-left: 200px;
}

.right .content {
    background-color: blue;
    width: auto;
    height: 300px;
}