JSFiddle - React, Tailwind, and code Playground

HTML

<section id="timeline">
        <article>
            <div class="inner">
            </div>
        </article>
    </section>
    <section id="timeline">
        <article>
            <div class="inner">
            </div>
        </article>
    </section>
    <section id="timeline">
        <article>
            <div class="inner">
            </div>
        </article>
    </section>
    <section id="timeline">
        <article>
            <div class="inner">
            </div>
        </article>
    </section>
    <section id="timeline">
        <article>
            <div class="inner">
            </div>
        </article>
    </section>

CSS

section article div.inner {
    background: red;
    width: 50px;
    height: 50px;
}

section:nth-of-type(odd) article div.inner {
    float: left;
}

section:nth-of-type(even) article div.inner {
    float: right;
}