wp-calypso/client/my-sites/purchases/styles.scss

.layout__primary .main {
	& div.section-nav {
		@media ( max-width: 480px ) {
			&.is-open {
				& > .section-nav__panel {
					padding: 0;

					& > .section-nav-group {
						margin-top: 0;
					}
				}
			}
		}
	}
}