WooCommerce: Some change only for variable products

Hello!
I have one problem. I would be grateful if you could help me.
I have this code:

// Add min value to the quantity field (default = 1)
add_filter('woocommerce_quantity_input_min', 'min_decimal');
function min_decimal($val) {
    return 0.1;
}
 
// Add step value to the quantity field (default = 1)
add_filter('woocommerce_quantity_input_step', 'nsk_allow_decimal');
function nsk_allow_decimal($val) {
    return 0.01;
}
 
// Removes the WooCommerce filter, that is validating the quantity to be an int
remove_filter('woocommerce_stock_amount', 'intval');
 
// Add a filter, that validates the quantity to be a float
add_filter('woocommerce_stock_amount', 'floatval');
 
// Add unit price fix when showing the unit price on processed orders
add_filter('woocommerce_order_amount_item_total', 'unit_price_fix', 10, 5);
function unit_price_fix($price, $order, $item, $inc_tax = false, $round = true) {
    $qty = (!empty($item['qty']) && $item['qty'] != 0) ? $item['qty'] : 1;
    if($inc_tax) {
        $price = ($item['line_total'] + $item['line_tax']) / $qty;
    } else {
        $price = $item['line_total'] / $qty;
    }
    $price = $round ? round( $price, 2 ) : $price;
    return $price;
}

And it’s working perfectly, but I would like to make this code work only for variable products. I think it’s about change somewhere in ‘woocommerce_quantity_input_step’ to include the “variable” somewhere, but I dont know where and if it’s correct. I’ve tried many combinations but they weren’t working correctly. I don’t know much php. Of course this code is included in child theme’s functions.php file.

Thank you much in advance!