woocommerce/plugins/woocommerce-blocks/assets/js/base/components/loading-mask/style.scss

.wc-block-loading-mask {
	position: relative;
	min-height: 18px + $gap;

	.components-spinner {
		position: absolute;
		margin: 0;
		top: 50%;
		left: 50%;
		transform: translate(-50%, -50%);
	}
}

.wc-blocks-loading-mask__children {
	opacity: 0.5;
}