woocommerce/plugins/woocommerce-admin/client/homepage/stats-overview/style.scss

// Set up some local color variables to make the CSS more clear
$outer-border: $core-grey-light-700;

.woocommerce-stats-overview {
	.woocommerce-card__body {
		padding: 0;
	}
	.woocommerce-summary {
		margin: 0;
	}
}

.woocommerce-stats-overview__footer {
	border-top: 1px solid $outer-border;
}

.woocommerce-stats-overview__more-btn {
	display: inline-block;
	padding: $gap;
}

.woocommerce-stats-overview__tabs {
	.components-tab-panel__tabs {
		display: flex;
		justify-content: space-between;
		border-bottom: 1px solid $outer-border;
	}

	.components-button {
		display: block;
		padding: $gap;
		width: 33.33%;
		margin-bottom: 4px;

		&:focus {
			outline: none;
			box-shadow: none;
		}

		&.is-active {
			border-bottom: 4px solid $studio-blue-50;
			// Avoid the text "jumping" when border-bottom applied.
			margin-bottom: 0;
		}

		&:first-child {
			text-align: left;
			padding-right: 0;
		}

		&:last-child {
			text-align: right;
			padding-left: 0;
		}
	}
}

.woocommerce-stats-overview__stats {
	margin: 0;

	.woocommerce-summary__item-container {
		width: 50%;
		display: inline-block;
	}

	.woocommerce-summary__item-container:nth-last-of-type(1) .woocommerce-summary__item {
		border-bottom: none;
	}

	&.is-even .woocommerce-summary__item-container:nth-last-of-type(2) .woocommerce-summary__item {
		border-bottom: none;
	}

	.woocommerce-summary__item-container:nth-of-type(even) .woocommerce-summary__item {
		border-right: none;
	}
}