oficinasuport-wp-theme/sass/plugins/woocommerce/_checkout.scss

@media screen and (min-width: 768px) {

	.col2-set {

		.form-row-first {
			float: left;
			margin-right: $columns__margin;
		}

		.form-row-last {
			float: right;
			margin-right: 0;
		}

		.form-row-first,
		.form-row-last {

			@include column-width(2);
		}
	}
}