Incorrect window corner radius on macOS 27 (Golden Gate) #175

Title: Incorrect window corner radius on macOS 27 (Golden Gate)

Description

Telegram for MacOS 13.1 does not appear to respect the system window corner radius on macOS 27. The outer window corners and the inner content background have visibly inconsistent radii, resulting in an uneven, non-native appearance.

Steps to reproduce

1. Run Telegram 13.1 on macOS 27.2
2. Open Telegram Settings.
3. Observe the top-left and top-right window corners.

Expected behavior

The window and its content should follow the standard macOS 27 corner radius, consistent with other native applications.

Actual behavior

The window's outer frame and inner content background use visibly different corner radii. The result looks incorrect compared with the system's expected window appearance.

Environment

• OS: macOS 27.2 (Golden Gate)
• App: Telegram 13.1
• UI language: Russian

Additional context

This appears to be a window rendering or clipping issue. Could you please investigate whether Telegram's custom window background or corner masking is preventing the application from following the system's standard window corner radius?

Add a concise visual-evidence noteSpecify the affected Settings screens