11. STOCK-BASED COMPENSATION - Weighted average assumptions (Details) - USD ($)	12 Months Ended
	Mar. 31, 2025	Mar. 31, 2024	Mar. 31, 2023
Other information
Income tax benefit recognized from allocation of share-based compensation expense	$ 0	$ 0
Windfall tax benefits realized	0	$ 0
Unrecognized compensation costs	$ 5,100,000
Weighted average period of recognition of unrecognized compensation costs	2 years 11 months 12 days
Weighted average fair value per underlying share of options granted (in dollars per share)	$ 2.23	$ 2.13	$ 1.38
Minimum
Stock-based compensation
Expected life	4 years 10 months 24 days	4 years 6 months	4 years 7 months 6 days
Maximum
Stock-based compensation
Expected life	5 years	4 years 10 months 24 days	5 years
Employee Stock Option [Member]
Stock-based compensation
Risk-free interest rate, low end of range (as a percent)	4.05%	3.69%	2.95%
Risk-free interest rate, high end of range (as a percent)	4.48%	4.80%	4.27%
Volatility, low end of range (as a percent)	91.00%	80.70%	49.20%
Volatility, high end of range (as a percent)	96.70%	85.90%	53.10%
Employee Stock Option [Member] | Minimum
Stock-based compensation
Expected life	4 years 10 months 20 days	4 years 5 months 15 days	4 years 6 months 18 days
Employee Stock Option [Member] | Maximum
Stock-based compensation
Expected life	5 years	4 years 11 months 8 days	5 years
Employee stock purchase plan options
Stock-based compensation
Risk-free interest rate, low end of range (as a percent)	4.44%	5.26%	1.54%
Risk-free interest rate, high end of range (as a percent)	5.41%	5.38%	4.54%
Expected life	6 months	6 months	6 months
Volatility, low end of range (as a percent)	6.10%	28.80%	49.30%
Volatility, high end of range (as a percent)	12.40%	83.90%	58.20%