woocommerce/plugins/woocommerce-blocks/packages/checkout/components/totals-wrapper/style.scss

.wc-block-components-totals-wrapper {
	@include with-translucent-border(1px 0 0);
	padding: $gap 0;

	&.has-bottom-border {
		&::after {
			border-bottom-width: 1px;
		}
	}
	// TotalWrappers like Discount and Fee are sometimes empty
	// this prevents displaying the empty areas in Order Summary
	&:empty {
		padding: 0;
		&::after {
			content: none;
		}
	}

	&.slot-wrapper {
		padding: 0;

		> * > * {
			@include with-translucent-border(0 0 1px);
			padding: $gap 0;


			// removes the border bottom for the last slot inserted
			&:last-child::after {
				border-bottom-width: 0;
			}
		}
	}
}

.wc-block-components-discounts-meta {
	.wc-block-components-totals-wrapper {
		&:first-child {
			@include with-translucent-border(1px 0 0);
		}
	}
}