How to customize the default WordPress Login Form and Registration Form without using a plugin

It's possible to customize the default WordPRess Login Form and Registration Form without using a plugin.

This is the modified registration form:

It's related to my previous article titled "How to remove WordPress logo from login page." Please read this post before proceeding to the following steps.

To customize the Login & Registration Forms:

First, you need to add the following code snippets to the "functions.php" file of your WordPress theme.

function my_login_logo() { ?>
 <style type="text/css">
 body.login div#login h1 a {
 background-image: url(<?php echo get_stylesheet_directory_uri(); ?>/images/site-login-logo.png);
 padding-bottom: 30px;
 }
// Your code here
 </style>
 <?php }
 add_action( 'login_enqueue_scripts', 'my_login_logo' );

* Note: All quote marks should be "straight quotes" not "curly quotes."

You can change the appearance of the forms by adding your own css code in place of "// Your code here" above. (Reference: you can refer to this page for some stylish login form layouts and CSS codes.)

Also, you can also add new fields by using User Registration Aide. Here is a sample.

Now you can change the appearance of the WordPress Login Form and Registration Form as you wish.