How to change font size of label, placeholder: Card no, Exp and CVC Input Feilds

I need to adjust the font size of the label placeholder in the Stripe form. I tried using JavaScript and CSS, but had no luck. Can anyone help with this? the code I’m using is in below. is that m missing something here? A screenshot is attached showing the issue.

add_filter( 'wc_stripe_upe_params', function ( $stripe_params ) {
    if ( isset( $stripe_params['appearance'] ) && is_object( $stripe_params['appearance'] ) ) {
        $stripe_params['appearance']->variables = (object) [
            'colorBackground' => '#fce4ec', // Light pink for testing
            'textColor' => '#880e4f',      // Dark red text color for testing
            'fontSize' => '20px',         // Large font size for testing
        ];
    }

    return $stripe_params;
});

form where i need adjustment
https://www.awesomescreenshot.com/image/51772453?key=27af9b2ba9bea11476035efb704b53ed

full checkout page
https://www.awesomescreenshot.com/image/51772454?key=7ec6c9d6f082cc85dcf82faa92bae3af

Thanks guys

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