add_action( 'after_setup_theme', function() {
	add_theme_support( 'woocommerce', array(
		'thumbnail_image_width' => 75,
		'gallery_thumbnail_image_width' => 75,
		'single_image_width' => 150,
	));
});

add_filter( 'woocommerce_get_image_size_gallery_thumbnail', function( $size ) {
return array(
'width' => 75,
'crop' => 0,
);
} );

add_action( 'after_setup_theme', function() {
	add_theme_support( 'woocommerce', array(
		'thumbnail_image_width' => 75,
		'gallery_thumbnail_image_width' => 75,
		'single_image_width' => 150,
	));
});

.single-product .site-main .woocommerce-product-gallery.woocommerce-product-gallery--columns-4 .flex-control-thumbs li {
    flex: 0 1 calc(20% - 30px);
}

.single-product .site-main .woocommerce-product-gallery .flex-control-thumbs li {
    list-style: none;
    cursor: pointer;
    margin: 0 0px 10px 10px;
}