JSFiddle - React, Tailwind, and code Playground

HTML

<div class="sidebar">Menu</div>
<div class="content">
    before
    <div>
        <div class="float" style="background: black;"></div>
        <div class="float" style="background: white;"></div>
        <div class="clear"></div>
    </div>
    after
</div>

CSS

.sidebar {width: 100px; float: right; background: red; height: 200px;}
.content {margin-right: 150px; background: silver; height: 500px;}
.float {float: left; width: 20px; height: 20px;}
.clear {clear: both;}