FULL WIDTH BUTTON
Run
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>HTML</title>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css">
<style>
   input {
     background-color: blue;
	 color: white;
	 padding: 10px;
	
	 
   }
   .full {
      display: block;
	  width: 100%;
   }
</style>
</head>
<body>
    <h2> Default Button</h2>
    <input type="submit" class="default">
	<h2> Full-width Button</h2>
    <input type="submit" class="full">	
</body>
</html>