_custom_logo_header_styles()

Source

File: wp-includes/theme.php

function _custom_logo_header_styles() {
	if ( ! current_theme_supports( 'custom-header', 'header-text' ) && get_theme_support( 'custom-logo', 'header-text' ) && ! get_theme_mod( 'header_text', true ) ) {
		$classes = (array) get_theme_support( 'custom-logo', 'header-text' );
		$classes = array_map( 'sanitize_html_class', $classes );
		$classes = '.' . implode( ', .', $classes );

		$type_attr = current_theme_supports( 'html5', 'style' ) ? '' : ' type="text/css"';
		?>
		<!-- Custom Logo: hide header text -->
		<style id="custom-logo-css"<?php echo $type_attr; ?>>
			<?php echo $classes; ?> {
				position: absolute;
				clip: rect(1px, 1px, 1px, 1px);
			}
		</style>
		<?php
	}
}