<rdar://problem/179759501>

The status bar behavior has not changed between iOS 26 and iOS 27. The black-translucent status bar mode has been deprecated for multiple releases because it semantically can’t work with dark mode and across different webpage styles. Please remove this key, and the status bar should automatically appear in the same color as the webpage. Home Screen web apps does not support drawing arbitrary content below the status bar.

Home Screen web apps should keep supporting the standard `viewport-fit=cover` though. iOS 26.1 had the same regression for edge-to-edge layout: https://bugs.webkit.org/show_bug.cgi?id=300445 As I noted in that bug report last year, this seems to be correlated with the `position: fixed` regression of early iOS 26 releases, which has also reappeared in iOS 27: https://bugs.webkit.org/show_bug.cgi?id=297779

Reproduced on iOS 27 beta 2 AND beta 3 (iPhone 16 Pro Max, 956pt screen). Our measurements may reconcile comment 2 ("behavior has not changed") with the regression reports: the breakage tracks WHEN the Home Screen icon was added, not which OS version launches it. - An icon added BEFORE the iOS 27 betas (recipe: viewport-fit=cover + apple-mobile-web-app-capable + apple-mobile-web-app-status-bar-style=black-translucent + manifest display:standalone) still renders true edge-to-edge on beta 3 — install-time chrome persists across OS updates. - ANY icon freshly added on beta 2 or beta 3 (same recipe; tested with a production app and a minimal probe page) opens letterboxed: window.innerHeight=894 vs screen.height=956 (delta = 62pt = exactly this device's status-bar inset). visualViewport.height=894. - The env() flavor depends on which beta the icon was added on: added on beta 2 -> env(safe-area-inset-top) resolves 62px INSIDE the already-inset web view (double inset — matches bug 313800); added on beta 3 -> env(safe-area-inset-top)=0 AND env(safe-area-inset-bottom)=0. So "the status bar behavior has not changed" may hold for launches of previously-installed apps, while every (re)install performed on the 27 betas bakes the letterboxed geometry. Happy to provide the probe page / more measurements. Also filed via Feedback Assistant. (Apologies for the earlier malformed comment - API hiccup on my side.)

No longer reproducible on beta 4. Ditto for the `position: fixed` regression mentioned above. Thanks for the timely fixes!

Closing as per comment 6. Please feel free to reopen if that's incorrect.