Uppercase to Lowercase

Hi..

I’m crazy to figure this out.
First about CSS. Look like text-transform:capitalize is not working when the word already in uppercase.

Example user wrote title HELLO HOW ARE YOU.. then i put in CSS text-transform:capitalize the font will not change to be Hello How Are You.

So here i make simple code to replace the string.

function my_function ($text) {
	$text = str_replace('A', 'a', $text);
	return $text;
}
add_filter('the_title', 'my_function');

Question how to make it for all letters?

'ABCDEFGHIJKLMNOPQRSTUVWXYZ','abcdefghijklmnopqrstuvwxyz'

than you ??