JSFiddle - React, Tailwind, and code Playground

HTML

<div id="container">
    <div id="left">
        LEFT
    </div>
    <div id="right">
        RIGHT
    </div>
</div>

CSS

#container{
    display: flex;
    align-items: center;
    
    height:200px;
    /* vertical-align:middle; */
    /* display:table-cell; */
    background-color:yellow;
}

#left{
    height:150px;
    color:white;
    background-color:blue;
    font-size:20px;
    /* float:left; */
    width:100px;
    }

#right{
    height:80px;
    color:white;
    background-color:red;
    font-size:20px;
    /* float:left; */
    width:100px;
}