JSFiddle - React, Tailwind, and code Playground

HTML

<div class="fixed"></div>
<div class="fluid"></div>

CSS

.fixed {
    float: left;
    width: 250px;
    height: 100px;
}

.fluid {
    margin-left: 250px;
}










/* SHOW ME*/
.fluid,
.fixed {
    height: 200px;
    border: 1px solid black;
    box-sizing: border-box;
    -moz-box-sizing: border-box;
}