How does 'Template Literal Types' facilitate CSS-in-JS and String Safety?

Template literal types allow for string manipulation and pattern matching at the type level.

Introduced in TS 4.1, they use the same syntax as JS template strings to produce new string literal unions. This allows the type system to validate complex string patterns like CSS properties (e.g., margin-top vs margin-right) or dynamically generated object keys (e.g., on${Capitalize<EventName>}). This bridges the gap between dynamic string-based APIs and static type safety.