JSFiddle - React, Tailwind, and code Playground

HTML

<div id="container">
    <div id="left10"></div>
    <div id="rest90"></div>
</div>

CSS

div {
	    height:400px
	}
	#container {
	    width:100%
	}
	#left10 {
	    width:10%;
	    float:left;
	    background:red;
	    left:0px;
	    position:absolute;
	}
	#rest90 {
	    padding-left:1px;
	    width:90%;
	    float:left;
	    background:yellow;
	    left:10%;
	    position:absolute;
	}