JSFiddle - React, Tailwind, and code Playground

HTML

<div class="cont">
        <div class="header"></div>
    </div>

CSS

html, body{
margin:0;
padding:0;
background:#ccc;
height:99%;
}

.cont{
height:100%;
width:99%;
border-radius:5px 0px 0px 5px;
background:orange;
float:right;
}

.header{
height:200px;
background:black;
border-radius:5px 0px 0px 0px;
}