woocommerce/plugins/woocommerce-admin/client/stylesheets/_index.scss

// Import our wp-admin reset.
@import './shared/_reset.scss';

// Some WooCommerce Admin page specific resets.
.woocommerce-page {
	.wp-has-current-submenu::after {
		right: 0;
		border: 8px solid transparent;
		content: ' ';
		height: 0;
		width: 0;
		position: absolute;
		pointer-events: none;
		border-right-color: #f1f1f1;
		top: 0;
		margin-top: 10px;

		@include breakpoint( '<960px' ) {
			border-width: 4px;
			margin-top: 14px;
		}
	}
}

// Import any global styles.
@import './shared/_global.scss';

// Import the embed-specific styles.
@import './shared/_embed.scss';

// Import gutenberg SCSS so that we can apply our theme colors.
@import './shared/gutenberg-components.scss';