JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">
    <div class="top">TOP</div>
    <div class="middle">MIDDLE</div>
    <div class="bottom">BOTTOM</div>
</div>

CSS

.container {
    background-color: #1abc9c;
    width: 600px;
    height: 500px;
    padding: 10px;
    color: #fff;
}
.top {
    background-color: #3498db;
    height: 100px;
}
.middle {
    background-color: #9b59b6;
    height: calc(100% - 100px - 100px);
}
.bottom {
    height: 100px;
    background-color: #34495e;
}