Condensed Statements of Stockholders' Equity (Deficit) (unaudited) (Parenthetical) $ in Thousands	3 Months Ended
Mar. 31, 2021 USD ($)
Follow On Offering
Payment Of underwriter discounts commissions and issuance cost	$ 7,400

Payment of underwriter discounts, commissions and issuance cost.

No definition available.

Name:	harp_PaymentOfUnderwriterDiscountsCommissionsAndIssuanceCost
Namespace Prefix:	harp_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	duration