JSFiddle - React, Tailwind, and code Playground

HTML

<div id="leftAside"></div>
<div id="rightWrapper">
   <div id="leftTop"></div>
   <div id="leftBottom"></div>
</div>

CSS

#rightWrapper {
    float:right;
    width: 32%;
    height: 65px;
}
#leftTop {
    background-color: green;
    width: 100%;
    height: 20px;
}

#leftBottom {
    background-color: red;
    width: 100%;
    height: 20px;
}

#leftAside {
    background-color: blue;
    width: 60%;
    height: 40px;
    float:left;
}