JSFiddle - React, Tailwind, and code Playground

HTML

<div class="grow"></div>

CSS

body, html {
    width: 100%;
    height:100%;
    min-height:100%
}
.grow {
    background-color:grey;
    height:20px;
    width:100%;
}

JavaScript

var $grow = $('.grow'),
    $window = $(window);
$(window)
    .resize(function () {
        var windowWidth = $window.width();
        if (windowWidth > 90) {
            $grow.width(~~ (windowWidth / 4));
        }
    })
    .resize();