Shadow styling needs an explicit public contract

A reusable shadow component needs deliberate styling hooks because ordinary page selectors cannot reach its internal elements.

Without a documented customization surface, consumers may depend on private structure or abandon the component when branding requirements change.

CSS scoping describes custom properties as values that outside pages can pass into components for interpretation.

Expose theme values through named properties and selected elements through parts, rather than publishing every implementation detail.

If boundaries contain selectors, semantic tokens can preserve design intent across those boundaries.

Treat public part names and theme properties as compatibility commitments when internal markup changes between component releases.

A narrow styling contract preserves useful encapsulation while giving consumers controlled ways to adapt the rendered interface.