logo-login.php

<?php
//* Do NOT include the opening php tag

//* Login Screen: Change login logo
add_action( 'login_head', 'b3m_custom_login_logo' );
function b3m_custom_login_logo() {
	echo '<style type="text/css">
    h1 a { background-image:url('.get_stylesheet_directory_uri().'/images/login.png) !important; background-size: 311px 100px !important;height: 100px !important; width: 311px !important; margin-bottom: 0 !important; padding-bottom: 0 !important; }
    .login form { margin-top: 10px !important; }
    </style>';
}