Changing the logo on the WordPress login page.

	// Zmiana logo na stronie logowania Wordpress.

add_filter( 'login_head', function () {

	$custom_logo = 'https://yourimageurl.com';

	$logo_width  = 200;

	$logo_height = 84;

	printf(

		'<style>.login h1 a {background-image:url(%1$s) !important; margin:0 auto; width: %2$spx; height: %3$spx; background-size: 100%%;}</style>',

		$custom_logo,

		$logo_width,

		$logo_height

	);

}, 990 );