JSFiddle - React, Tailwind, and code Playground

HTML

<div class="parent">
    <div class="child">
        
    </div>
</div>

CSS

.parent {
    background-color:red;
    width:100%;
    height:100px;
    padding-top: 1px;
    margin-top: -1px;
}

.child {
    background-color:yellow;
    width:30%;
    height:30px;
    margin:0 auto;
    margin-top:30px;
}