JSFiddle - React, Tailwind, and code Playground

HTML

<div id="lbp-text-body">testing</div>

CSS

html, body {
    width: 100%;
    height: 100%;
}
#lbp-text-body {
    font-size: 60px;
    background: blue;
    color: white;
    height: 100%;
    width: 100%;
    display: block;
}
@media only screen and (max-width: 300px) {
    #lbp-text-body {
        background: black;
        font-size: 20px;
    }
}
    @media only screen and (min-width: 800px) {
        #lbp-text-body {
            background: green;
            font-size: 100px;
        }
    }