JSFiddle - React, Tailwind, and code Playground

HTML

<div class="wrapper">
    <div class="left">left</div>
    <div class="right">right</div>
</div>

<div class="wrapper">
    <div class="left">left</div>
    <div class="right">right</div>
</div>

CSS

.wrapper {
    overflow: hidden;
    margin: 0 0 16px 0
}
.left {
    width: 200px;
    float: left;
    background: #ccc
}
.right {
    background: red;
    overflow: hidden
}