image css for making it full width of screen code example
Example: HTML Image full screen width
<!DOCTYPE html>
<html>
<head>
<style>
body{ margin:0px }
div#middle > div{ float:left; width:100%; }
div#middle > div > div > img{ width:100%; }
</style>
</head>
<body>
<div id="middle">
<div>
<div>
<img src="example.jpg" alt="example">
</div>
</div>
</div>
</body>
</html>