Custom login pages css help needed

i really need some help on this css style for login form
because it does show now on total left on the page

and my goal is to get it centerd on the page anyone got an idea how to fix this?

underneath is the css as it is now…. gracias!

function customloginpages_login_css ( ) {
?>
	<style type="text/css">
	form.loginform p label {
		width: 150px;
		display: block;
		float: left;
		clear: both;
	}
	form.loginform p input.input {
		width: 150px;
		float: left;
		clear: right;
	}
	form.loginform p img {
		width: 155px;
		float: left;
	}
	form.loginform, form.loginform p {
		clear: both;
	}
	p.message, p#login_error {
		padding: 3px 5px;
	}
	p.message {
		background-color: Transparent;
		border: 0px solid yellow;
	}
	p#login_error {
		background-color: Transparent;
		border: 0px solid red;
		color: #FF0000;
	}
	</style>