JSFiddle - React, Tailwind, and code Playground

HTML

<body>
<div id="yellow">66% родителя</div>
<div id="pink">66% родителя</div>



</body>

CSS

#yellow {
	background-color: #fefd8f;
	margin-top: 10px;
	width: 66%;
	height: 10%;
	margin-left: 10px;

}
#pink {
background-color: #f6ccfc;
margin-top: 10px;
margin-left:auto;
margin-right: 10px;

width: 66%;
height: 10%
}