JSFiddle - React, Tailwind, and code Playground

by Denis

HTML

<div class="wrap">
	<div class="left"></div>
	<div class="wrapper">
	    <div class="content">
	        Блок с контентом
	    </div>

	    <div class="sidebar">
	        Сайдбар
	    </div>	 
	</div>
</div>

CSS

body {
  font: 12px/18px Arial, sans-serif;
  width: 100%;
  background: #F7F7F7;
  margin: 0;
  padding: 0;
    
}
.wrapper {
  margin: 0 auto;	
  width: 935px;

}
.content {
  display: inline-block;
  width: 640px;
  background: #fff;
  height: 500px;
  border-radius: 0 0 5px 0;
}

.left {
  content: " ";
  position: absolute;
  display: block;
  top: 0;
  left: 0;
  z-index: -1;
  background: #fff;
}

.sidebar {
  display: inline-block;
  width: 290px;
  background: #F7F7F7;
}

JavaScript

$(document).ready(function(){
		var offset = $(".content").offset();
		$('.left').css('width', offset.left);
  		height = $('.content').css('height');
  		$('.left').css('height', height);

  		$(window).resize(function(){
  			var offset = $(".content").offset();
			$('.left').css('width', offset.left);
  		});
	});