feat: support iOS 27 Liquid Glass 2.0

[rdlabo]

iOS 27 support will be handled in this repository. Once the official release is available, the repository name and package name will be updated accordingly.

Please note that Apple often makes many changes after the beta stage, so development will not proceed until the official release. Pull requests are of course welcome.

https://www.youtube.com/watch?v=xXQOMicU7WI

[rdlabo]

https://www.gizmodo.jp/article/wwdc26-ios27-design/

1. Became more rounded
2. Outlines became more defined

[drolpi]

Hi, Thanks for keeping this repo actively maintained through the iOS 27 beta cycle!
Instead of renaming the repo/package to iOS 27 once it's released, would it be possible to keep all theme versions available and have the library automatically detect the user's iOS version at runtime and apply the matching theme?
For example:

iOS 18 and below → Ionic's default theme
iOS 26 → ionic-theme-ios26 styling
iOS 27+ → ionic-theme-ios27 styling

This way, a single app/package could ship all theme variants together, and the correct one would just be selected automatically based on the detected OS version, instead of developers having to manually swap packages or losing iOS 26 support once the repo migrates to iOS 27. Would this kind of automatic version detection be feasible to implement?

[rdlabo]

Thanks for the suggestion! I cannot say for sure whether this will be feasible until I start implementing and testing it. I would like to minimize breaking changes as much as possible and support this kind of automatic theme selection if we can. However, I have not yet investigated whether iOS 27 exposes a reliable CSS feature query or similar signal—something like @supports (text-wrap: pretty)—that we could use to distinguish it. If you have already researched this or know of a reliable detection method, I would really appreciate any advice or pointers.

For reference, the current iOS 18 compatibility behavior is documented here:
https://docs.rdlabo.dev/projects/ionic-theme-ios26/docs/ios-18