Responsivity ?

Hi,
And thank you for this awesome plugin !

I make my themes with support for this plugin. I like it ! But I have responsive themes like Cannyon ( free on WordPress community ).

For example I have a big text on the header and the users can change the font size for this headline. For small devices this text is too big !

Please, some one, can advise me how to use the plugin with responsive support ?

Now I use the plugin in next way:

<?php
if ( class_exists( 'EGF_Register_Options' ) ) {

    $fonts = array(
        'mythemes-cannyon-header-headline'          => array(
            'name'          => 'mythemes-cannyon-header-headline',
            'title'         => __( 'Header Headline',  'cannyon_' ),
            'type'          => 'font',
            'description'   => null,
            'section'       => 'default',
            'tab'           => 'theme-typography',
            'transport'     => 'postMessage',
            'since'         => 1.0,
            'properties'    => array(
                'selector'      => 'div.mythemes-header a.header-title',
                'force_styles'  => null
            )
        ),
        'mythemes-cannyon-header-description'          => array(
            'name'          => 'mythemes-cannyon-header-description',
            'title'         => __( 'Header Description',  'cannyon_' ),
            'type'          => 'font',
            'description'   => null,
            'section'       => 'default',
            'tab'           => 'theme-typography',
            'transport'     => 'postMessage',
            'since'         => 1.0,
            'properties'    => array(
                'selector'      => 'div.mythemes-header a.header-description',
                'force_styles'  => null
            )
        )
    );

    function mythemes_get_option_parameters( $options )
    {
        global $fonts;

        $options = array_merge( $fonts, $options );

        return EGF_Register_Options::get_custom_option_parameters( $options );
    }

    add_action( 'tt_font_get_option_parameters' , 'mythemes_get_option_parameters' );
}

https://www.ads-software.com/plugins/easy-google-fonts/