JSFiddle - React, Tailwind, and code Playground

HTML

<div class="container">  
        <img class="img" src="http://www.bastards-design.de/wordpress/assets/aa_2.jpg"/>
    </div>

CSS

* {
	-webkit-box-sizing: border-box;
	-moz-box-sizing: border-box;
	box-sizing: border-box;
}

html,
body {
    height:100%;
    width:100%;
}

.container {
    background: green;
    float: left;
    height: 100%;
}

.img {
 	width:auto;
    height:50%;
}