[BUG] Wrapping the element in `<polyfill-position-area>` may break existing CSS

[jpzwarte]

As it says in the README.md:

- `position-area` is polyfilled by adding a wrapping element around the target,
  which adds a few differences:
  - This breaks selectors that rely on a direct relationship with the target,
    for instance `~ target`, `+ target`, `> target` or using `:nth` selectors.
  - Overflow alignment is not applied for a target that overflows its
    inset-modified containing block but would still fit within its original
    containing block. In other words, a polyfilled target may be placed in a
    `position-area` grid section outside its containing block, where the
    implementation would move the target inside the containing block.

I don't have an alternative solution at the moment, but i just wanted an issue to track it.