JSFiddle - React, Tailwind, and code Playground

HTML

<div class="wrapper">
    <div class="sidebar">
        <p>Sidebar</p>
    </div>
    
    <div class="container">
        <div class="left">
            <span>Left div</span>
            <select>
                <option>item 1</option>
                <option>item 2</option>
                <option>item 3</option>
            </select>                    
        </div>
        
        <div class="right">
            Right div
        </div>
        
        <table>
            <tr>
                <td>Table</td>
                <td>Table</td>
                <td>Table</td>
            </tr>
        </table>
        <p>Container</p>
    </div>
</div>

CSS

.wrapper:after {
    content: '';
    display: table;
    clear: both;
}

.sidebar {
    width: 20%;
    min-height: 100px;
    float: left;
    border: 1px solid silver;
}

.sidebar p {
    text-align: center;
}

.container {
    margin-left: 22%;
    border: 1px solid #ccc;
    padding: 5px;
}

.left, .right {
    border: 1px solid #ccc;
    padding: 5px;
}

.left {
    float: left;
}

.right {
    float: right;
}

.container table {
    margin: 50px 0;
    width: 100%;
    border: 1px solid #ccc;
}

.container p {
    text-align: center;
}