JSFiddle - React, Tailwind, and code Playground
by Aqeel Malik
HTML
<link rel="stylesheet" href="//cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/3.2.0/css/bootstrap.min.css">
<div class="part-b">
<div class="background"></div>
<div class="container">
<div class="row">
<div class="col-md-3">Side bar</div>
<div class="col-md-9">Content</div>
</div>
</div>
</div>
CSS
.part-b {
background: red;
overflow: hidden;
position: relative;
}
.part-b .background {
display: block;
position: absolute;
left: 0px;
width: 50%;
height: 100%;
background-color: blue;
}
.part-b .container {
background: silver;
opacity: 0.8;
}