Condensed Balance Sheets - USD ($)	Jun. 30, 2026	Dec. 31, 2025
Current assets:
Cash	$ 17,947	$ 4,966
Prepaid expenses	12,475	36,800
Total current assets	30,422	41,766
Cash held in Trust Account	660,761	859,443
Total Assets	691,183	901,209
Current liabilities:
Accounts payable and accrued expenses	6,873,661	4,261,904
Total current liabilities	13,026,770	9,925,013
Deferred underwriting fee	4,340,000	10,850,000
Warrant liabilities	3,396,987	2,527,991
Total Liabilities	20,763,757	23,303,004
Commitments and Contingencies (Note 6)
Shareholders’ Deficit
Preference shares, $0.0001 par value; 1,000,000 shares authorized; none issued and outstanding as of June 30, 2026 and December 31, 2025
Additional paid-in capital
Accumulated deficit	(20,734,110)	(23,262,013)
Total Shareholders’ Deficit	(20,733,335)	(23,261,238)
Total Liabilities, Ordinary Shares Subject to Possible Redemption and Shareholders’ Deficit	691,183	901,209
Class A ordinary shares
Current liabilities:
Class A ordinary shares subject to possible redemption, 46,529 and 64,302 shares at redemption value of approximately $14.20 and $13.37 per share as of June 30, 2026 and December 31, 2025, respectively	660,761	859,443
Shareholders’ Deficit
Ordinary Shares, value	760	760
Class B ordinary shares
Shareholders’ Deficit
Ordinary Shares, value	15	15
Related Party
Current liabilities:
Due to related party	420,000	360,000
Promissory notes – related parties	2,552,109	2,122,109
Convertible promissory note – related party	$ 3,181,000	$ 3,181,000

The amount of deferred underwriting fees.

No definition available.

Name:	cstwf_DeferredUnderwritingFees
Namespace Prefix:	cstwf_
Data Type:	xbrli:monetaryItemType
Balance Type:	credit
Period Type:	instant

- Definition

Sum of the carrying values as of the balance sheet date of obligations incurred through that date and due within one year (or the operating cycle, if longer), including liabilities incurred (and for which invoices have typically been received) and payable to vendors for goods and services received, taxes, interest, rent and utilities, accrued salaries and bonuses, payroll taxes and fringe benefits.