JSFiddle - React, Tailwind, and code Playground

HTML

<div id="main">
    <div id="sub-main">
        <div id="content">
            <div id="item-container">
                <div class="item">a</div>
                <div class="item">b</div>
                <div class="item">c</div>
            </div>
        </div>
    </div>
</div>

CSS

#main {
    width: 500px;
    height: 500px;
}

#sub-main {
    width: 500px;
    height: 500px;
    overflow: hidden;
}

#content {
    background-color: red;
    width: 500px;
    height: 500px;
    overflow: auto;
    padding:0 1em 1em 0;
}

#item-container {
    width: 1500px;
    height: 500px;
}

.item {
    width: 500px;
    height: 500px;
    font-size: 25em;
    text-align: center;
    float: left;
}