1. CSS Environment Variables env()

    Usage of environment variables like `safe-area-inset-top`.

  2. CSS Logical Properties

    Logical properties and values provide control of layout through logical, rather than physical, direction and dimension mappings. These properties are `writing-mode` relative equivalents of their corresponding physical properties.

  3. CSS Shapes Level 1

    Allows geometric shapes to be set in CSS to define an area for text to flow around. Includes properties `shape-outside`, `shape-margin` and `shape-image-threshold`

  4. Portals

    Portals enable seamless navigation between sites or pages. A new page can be loaded as an inset using the `<portal>` element (similar to an iframe) which can then seamlessly transition to the new navigated state when "activated".

  5. elementinternals api: ariaposinset

  6. element api: ariaposinset

  7. css property: box-shadow: `inset`

  8. css property: inset

  9. css property: inset-block

  10. css property: inset-block-end

  11. css property: inset-block-start

  12. css property: inset-inline

  13. css property: inset-inline-end

  14. css property: inset-inline-start

  15. css property: shape-outside: `inset()`

  16. types: `<basic-shape>`: `inset()`