JSFiddle - React, Tailwind, and code Playground

HTML

<div class=wrapper>
    <div class=resizable>
        <div class=left>im left</div>
        <div class=right>im right</div>
    </div>
</div>

CSS

.wrapper{
    position:relative;
}
.resizable{
    position:relative;
    overflow:hidden;
    background-color:yellow;
    top:0px;
    bottom:0px;
    left:0px;
    right:0px;
}
.left{
    float:left;
    width:50%;
    background-color:blue;
    height:100px;
}
.right{
    float:right;
    width:50%;
    background-color:red;
    height:100px;
}