JSFiddle - React, Tailwind, and code Playground
HTML
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.css">
<form id="frm" action="check_login.php" method="post">
<div class="input-group">
<span class="input-group-addon"><i class="fa fa-user"></i></span>
<input class="in_box1" name="username" type="text"
placeholder="Username" title="Enter Username or Email" maxlength="20"
required/>
</div>
<div class="input-group">
<span class="input-group-addon"><i class="fa fa-key"></i></span>
<input class="in_box2" name="password" type="password" placeholder="Password"
title="Enter
Password" maxlength="10" required/>
</div>
</form>