Applying CSS to PHP

Hi, I have some code to slightly change what Woo shows in my theme (basically for Multi Prices it shows “From £X).
However this removed the “inc VAT” label.
I have added some code and the inc VAT now shows (Suffix) but I need to apply the Font Size “Small” to it.

How do I do this. Code is below.

Thanks in advance.

function wc_ninja_custom_variable_price( $price, $product ) {
    // Main Price
    $prices = array( $product->get_variation_price( 'min', true ), $product->get_variation_price( 'max', true ) );
    $price = $prices[0] !== $prices[1] ? sprintf( __( 'From: %1$s', 'woocommerce' ), wc_price( $prices[0] ) ) : wc_price( $prices[0] );

    // Sale Price
    $prices = array( $product->get_variation_regular_price( 'min', true ), $product->get_variation_regular_price( 'max', true ) );
    sort( $prices );
    $saleprice = $prices[0] !== $prices[1] ? sprintf( __( 'From: %1$s', 'woocommerce' ), wc_price( $prices[0] ) ) : wc_price( $prices[0] );
$suffix = ' inc VAT';
    if ( $price !== $saleprice ) {
        $price = '' . $saleprice . ' ' . $price . '';
    }
    
    return $price . $suffix;
}

add_filter( 'woocommerce_variable_price_html', 'wc_ninja_custom_variable_price', 10, 2 );