JSFiddle - React, Tailwind, and code Playground

HTML

<div class="main">
    <div class="container clearfix">
        <div class="content">
            <section>
                <h1>This is the Main Content</h1>
                <hr>
                <h2>A sub heading</h2>
                <p>Lorem ipsum dolor sit amet, consectetur...</p>
            </section>
        </div>
        <div class="sidebar">
            <aside>
                <h2>This is a sidebar</h2>
                Sign up to the newsletter!
            </aside>
        </div>
    </div><!-- /.containter -->
</div><!-- /.main -->

CSS

.main .container {
    padding-right: 330px;
    overflow: hidden;
}
.content {
    float: left;
    width: 100%;
    background-color: orange;
}
.sidebar {
    float: right;
    margin-right: -330px;
    width: 300px;
    background-color: olive;
}
.content,
.sidebar {
    padding-bottom: 99999px;
    margin-bottom: -99999px;
}
section,
aside {
    padding: 30px
}