Note 3 - Summary of Significant Accounting Policies - Estimated Useful Lives of Property, Plant, and Equipment (Details)	12 Months Ended
	Dec. 31, 2020
Leasehold Improvements [Member]
Property and equipment, useful life (Year)	3 years
Vehicles [Member]
Property and equipment, useful life (Year)	5 years
Electronic Devices [Member]
Property and equipment, useful life (Year)	5 years
Minimum [Member] | Leasehold Improvements [Member]
Property and equipment, useful life (Year)
Minimum [Member] | Vehicles [Member]
Property and equipment, useful life (Year)
Minimum [Member] | Office Equipment [Member]
Property and equipment, useful life (Year)	3 years
Minimum [Member] | Electronic Devices [Member]
Property and equipment, useful life (Year)
Maximum [Member] | Leasehold Improvements [Member]
Property and equipment, useful life (Year)
Maximum [Member] | Vehicles [Member]
Property and equipment, useful life (Year)
Maximum [Member] | Office Equipment [Member]
Property and equipment, useful life (Year)	5 years
Maximum [Member] | Electronic Devices [Member]
Property and equipment, useful life (Year)