JSFiddle - React, Tailwind, and code Playground

HTML

<div id="container"><div id="first" class="thing"></div><div class="thing"></div><div class="thing"></div><div class="thing"></div><div id="last" class="thing"></div>
</div>

CSS

#container {
    background-color: Green;
    
    width: 500px;
    line-height: 0;
}

.thing {
    display: inline-block;
    background-color: Red;
    height: 20px;
    width: 18%;
    margin-left: 1.25%;
    margin-right: 1.25%;
}

#first {margin-left: 0px;}
#last {margin-right: 0px;}