DFL on "Add Inline Style in Shortcode"

Hi Everybody. I have a problem. My shortcodes available custom colors etc. I need create inline css lines after my 'main' handler.

functions.php

function push_dfl_site_style() {
	wp_enqueue_style('main', get_stylesheet_uri());
}
add_action('get_header', 'push_dfl_site_style');

a example shortcode

function push_dfl_columns($atts, $content = null, $tag) {
	extract(shortcode_atts(array(
    	'class' => ''
  	), $atts ));

	global $wp_styles;
   	$wp_styles->add_inline_style('main', 'body {background-color: "red"}');
   	$wp_styles->enqueue(array('main'));

         bla bla.....
}

This not working

I try another lines

a example shortcode

function push_dfl_columns($atts, $content = null, $tag) {
	extract(shortcode_atts(array(
    	'class' => ''
  	), $atts ));

	function my_styles_method() {
        $custom_css = "
                body{
                        background-color: 'red';
                }";
        wp_add_inline_style( 'main', $custom_css );
	}
	add_action( 'wp_enqueue_scripts', 'my_styles_method' );

         bla bla.....
}

I get this error.
Fatal error: Cannot redeclare my_styles_method() (previously declared in.....

I need custom inline styles after my 'main' handler or in head tag.

Thanks for reading my problem. I hope you give me a advice :)