JSFiddle - React, Tailwind, and code Playground

HTML

<div id="background">
    <div id="box">
        <div class="title">TITLE OF WEBSITE</div>
        <div class="text">Text corresponding to the specfic background shown.</div>
        <div class="button">
            <button type="button">Randomizing button</button>
        </div>
    </div>
</div>

CSS

html, body {
    height: 100%;
}
#background {
    height: 100%;
}
#box {
    background: #fff;
    width: 40%;
    min-width: 400px;
    height: 200px;
    margin-left: auto;
    margin-right: auto;
    top: 40%;
    position: relative;
}
.title {
    width: 100%;
    height: 50px;
    float: left;
    background: #e1e1e1;
    text-align: center;
    font-size: 24px;
    line-height:50px;
}
.text {
    background: #c8c8c8;
    width: 100%;
    height: 100px;
    float: left;
    text-align: center;
    font-size: 18px;
    position: relative;
    padding-top: 20px;
}
.button {
    width: 100%;
    height: 50px;
    float: left;
    text-align: center;
    background: #afafaf;
}