I am a beginner and struggling with understanding the CSS for the code below. Can someone help me out?
<div id="page-container">
<?php include_once("home_start.php"); ?>
<h1>Login</h1>
<form action='login process.php' method='POST'>
Username: <input type='text' name='username'><br />
Password: <input type='password' name='password'><br />
<input type='submit' name='submit' value='Login'>
<input name='reset' type='reset' value='Reset'>
</form>
<h4><a href='register.php'>Register</a></h4>
<?php include_once("home_end.php"); ?>
</div>