JSFiddle - React, Tailwind, and code Playground

HTML

<div id="container">

    <div id="mainCol">
        <div class="inner">
            <p>Some text</p>
            <p>Some text</p>
            <p>Some text</p>
            <p>Some text</p>
        </div><!-- .inner end -->
    </div><!-- .mainCol end -->

    <div id="sideCol">
        <p>Some text</p>
        <p>Some text</p>
        <p>Some text</p>
        <p>Some text</p>
    </div>

</div><!-- #container end -->

<br/><br/>

<div id="container">

    <div id="mainCol">
        <div class="inner">
            <p>Some text</p>
            <p>Some text</p>
            <p>Some text</p>
            <p>Some text</p>
        </div><!-- .inner end -->
    </div><!-- .mainCol end -->

</div><!-- #container end -->

<br/><br/>

<div id="container">

    <div id="mainCol">
        <div class="inner noSide">
            <p>Some text</p>
            <p>Some text</p>
            <p>Some text</p>
            <p>Some text</p>
        </div><!-- .inner end -->
    </div><!-- .mainCol end -->

</div><!-- #container end -->

CSS

#container { overflow: hidden; width: 100%; }

#mainCol { float: right; width: 100%; margin: 0 0 0 -200px; }
#mainCol .inner { margin: 0 0 0 200px; background: #F63; }
#mainCol .noSide { margin: 0 0 0 0; }
#sideCol { float: left; width: 200px; background: #FCF; }