TAXATION - Components of deferred tax assets (Details) ¥ in Thousands, $ in Thousands	Dec. 31, 2025 CNY (¥)	Dec. 31, 2025 USD ($)	Dec. 31, 2024 CNY (¥)	Dec. 31, 2024 USD ($)	Dec. 31, 2023 CNY (¥)
TAXATION
Temporary differences related to expenses and accruals	¥ 460	$ 66	¥ 530
Temporary differences related to impairment on advances to suppliers	306	44	306
Temporary differences related to provision for credit losses	601	86	600
Others	23	3	0
Temporary differences related to depreciation, amortization, and impairment of equipment and intangible assets	(3,317)	(474)	(3,392)
Startup expenses and advertising fees	14	2	33
Temporary differences related to equity investments	14,041	2,008	7,747
Temporary differences related to provision for prepayment for equipment	0	0	0
Tax loss carry forwards	97,392	13,926	142,365
Total deferred tax assets	109,520	15,661	148,189
Less: Valuation allowance	(109,520)	(15,661)	(148,189)	$ (21,191)	¥ (84,879)
Total deferred tax assets	¥ 0	$ 0	¥ 0

Deferred Tax Assets Advance Payments

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- Definition

Deferred Tax Assets Related To Depreciation And Amortization

+ References

No definition available.

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- Definition

Deferred Tax Assets, Start Up Costs

+ References

No definition available.

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- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from equity method investments.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 6
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-6

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- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (b)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-2

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- Definition

Amount after allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences and carryforwards.

+ References

Reference 1: http://www.xbrl.org/2009/role/commonPracticeRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-2

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Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary differences, classified as other.

+ References

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- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from property, plant, and equipment.

+ References

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- Definition

Amount, before allocation of a valuation allowances, of deferred tax assets attributable to deductible tax credit carryforwards including, but not limited to, research, foreign, general business, alternative minimum tax, and other deductible tax credit carryforwards.

+ References

+ Details

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- Definition

Amount before allocation of valuation allowances of deferred tax asset attributable to deductible temporary differences from reserves and accruals.

+ References

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- Definition

Amount, before allocation of valuation allowance, of deferred tax asset attributable to deductible temporary difference from allowance for credit loss on accounts receivable.

+ References

+ Details

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- Definition

Amount of deferred tax assets for which it is more likely than not that a tax benefit will not be realized.

+ References

Reference 1: http://www.xbrl.org/2003/role/disclosureRef
-Topic 740
-SubTopic 10
-Name Accounting Standards Codification
-Section 50
-Paragraph 2
-Subparagraph (c)
-Publisher FASB
-URI https://asc.fasb.org/1943274/2147482685/740-10-50-2

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- References

No definition available.

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