refactor: migrate background glass effect to new macos-background-style config

macos/Sources/Features/Terminal/Window Styles/TerminalWindow.swift

@@ -480,11 +480,9 @@ class TerminalWindow: NSWindow {
             backgroundColor = .white.withAlphaComponent(0.001)
 
             // Add liquid glass behind terminal content
-            if #available(macOS 26.0, *), derivedConfig.backgroundGlassStyle != "off" {
+            if #available(macOS 26.0, *), derivedConfig.macosBackgroundStyle != .blur {
                 setupGlassLayer()
-            }
+            } else if let appDelegate = NSApp.delegate as? AppDelegate {
-
-            if let appDelegate = NSApp.delegate as? AppDelegate {
                 ghostty_set_window_background_blur(
                     appDelegate.ghostty.app,
                     Unmanaged.passUnretained(self).toOpaque())
@@ -591,18 +589,18 @@ class TerminalWindow: NSWindow {
         let effectView = NSGlassEffectView()
 
         // Map Ghostty config to NSGlassEffectView style
-        let glassStyle = derivedConfig.backgroundGlassStyle
+        let backgroundStyle = derivedConfig.macosBackgroundStyle
-        switch glassStyle {
+        switch backgroundStyle {
-        case "regular":
+        case .regularGlass:
             effectView.style = NSGlassEffectView.Style.regular
-        case "clear":
+        case .clearGlass:
             effectView.style = NSGlassEffectView.Style.clear
         default:
-            // Should not reach here since we check for "off" before calling setupGlassLayer()
+            // Should not reach here since we check for "default" before calling setupGlassLayer()
             return
         }
 
-        effectView.cornerRadius = 18
+        effectView.cornerRadius = derivedConfig.windowCornerRadius
         effectView.tintColor = preferredBackgroundColor
 
         effectView.frame = windowContentView.bounds
@@ -627,14 +625,16 @@ class TerminalWindow: NSWindow {
         let backgroundColor: NSColor
         let backgroundOpacity: Double
         let macosWindowButtons: Ghostty.MacOSWindowButtons
-        let backgroundGlassStyle: String
+        let macosBackgroundStyle: Ghostty.MacBackgroundStyle
+        let windowCornerRadius: CGFloat
 
         init() {
             self.title = nil
             self.backgroundColor = NSColor.windowBackgroundColor
             self.backgroundOpacity = 1
             self.macosWindowButtons = .visible
-            self.backgroundGlassStyle = "off"
+            self.macosBackgroundStyle = .blur
+            self.windowCornerRadius = 16
         }
 
         init(_ config: Ghostty.Config) {
@@ -642,7 +642,17 @@ class TerminalWindow: NSWindow {
             self.backgroundColor = NSColor(config.backgroundColor)
             self.backgroundOpacity = config.backgroundOpacity
             self.macosWindowButtons = config.macosWindowButtons
-            self.backgroundGlassStyle = config.backgroundGlassStyle
+            self.macosBackgroundStyle = config.macosBackgroundStyle
+
+            // Set corner radius based on macos-titlebar-style
+            // Native, transparent, and hidden styles use 16pt radius
+            // Tabs style uses 20pt radius
+            switch config.macosTitlebarStyle {
+            case "tabs":
+                self.windowCornerRadius = 20
+            default:
+                self.windowCornerRadius = 16
+            }
         }
     }
 }

macos/Sources/Ghostty/Ghostty.Config.swift

@@ -261,17 +261,17 @@ extension Ghostty {
             return MacOSWindowButtons(rawValue: str) ?? defaultValue
         }
 
-        var backgroundGlassStyle: String {
+        var macosBackgroundStyle: MacBackgroundStyle {
-            let defaultValue = "off"
+            let defaultValue = MacBackgroundStyle.blur
             guard let config = self.config else { return defaultValue }
             var v: UnsafePointer<Int8>? = nil
-            let key = "background-glass-style"
+            let key = "macos-background-style"
             guard ghostty_config_get(config, &v, key, UInt(key.count)) else { return defaultValue }
             guard let ptr = v else { return defaultValue }
-            return String(cString: ptr)
+            let str = String(cString: ptr)
+            return MacBackgroundStyle(rawValue: str) ?? defaultValue
         }
 
-
         var macosTitlebarStyle: String {
             let defaultValue = "transparent"
             guard let config = self.config else { return defaultValue }

macos/Sources/Ghostty/Package.swift

@@ -352,6 +352,13 @@ extension Ghostty {
         case hidden
     }
 
+    /// Enum for the macos-background-style config option
+    enum MacBackgroundStyle: String {
+        case blur
+        case regularGlass = "regular-glass"
+        case clearGlass = "clear-glass"
+    }
+
     /// Enum for auto-update-channel config option
     enum AutoUpdateChannel: String {
         case tip

src/config/Config.zig

@@ -950,24 +950,6 @@ palette: Palette = .{},
 /// doing so.
 @"background-blur": BackgroundBlur = .false,
 
-/// The style of the glass effect when `background-opacity` is less than 1
-/// and the terminal is using a modern glass effect (macOS 26.0+ only).
-///
-/// Valid values are:
-///
-///   * `off` - No glass effect
-///   * `regular` - Standard glass effect with some opacity
-///   * `clear` - Highly transparent glass effect
-///
-/// This setting only takes effect on macOS 26.0+ when transparency is enabled
-/// (`background-opacity` < 1). On older macOS versions or when transparency
-/// is disabled, this setting has no effect.
-///
-/// The default value is `off`.
-///
-/// Available since: 1.2.2
-@"background-glass-style": BackgroundGlassStyle = .off,
-
 /// The opacity level (opposite of transparency) of an unfocused split.
 /// Unfocused splits by default are slightly faded out to make it easier to see
 /// which split is focused. To disable this feature, set this value to 1.
@@ -3124,6 +3106,28 @@ keybind: Keybinds = .{},
 /// Available since: 1.2.0
 @"macos-shortcuts": MacShortcuts = .ask,
 
+/// The background style for macOS windows when `background-opacity` is less than 1.
+/// This controls the visual effect applied behind the terminal background.
+///
+/// Valid values are:
+///
+///   * `blur` - Uses the standard background behavior. The `background-blur`
+///     configuration will control whether blur is applied (available on all macOS versions)
+///   * `regular-glass` - Standard glass effect with some opacity (macOS 26.0+ only)
+///   * `clear-glass` - Highly transparent glass effect (macOS 26.0+ only)
+///
+/// The `blur` option does not force any blur effect - it simply respects the
+/// `background-blur` configuration. The glass options override `background-blur`
+/// and apply their own visual effects.
+///
+/// On macOS versions prior to 26.0, only `blur` has an effect. The glass
+/// options will fall back to `blur` behavior on older versions.
+///
+/// The default value is `blur`.
+///
+/// Available since: 1.2.2
+@"macos-background-style": MacBackgroundStyle = .blur,
+
 /// Put every surface (tab, split, window) into a dedicated Linux cgroup.
 ///
 /// This makes it so that resource management can be done on a per-surface
@@ -7708,6 +7712,13 @@ pub const MacShortcuts = enum {
     ask,
 };
 
+/// See macos-background-style
+pub const MacBackgroundStyle = enum {
+    blur,
+    @"regular-glass",
+    @"clear-glass",
+};
+
 /// See gtk-single-instance
 pub const GtkSingleInstance = enum {
     false,
@@ -8401,13 +8412,6 @@ pub const BackgroundBlur = union(enum) {
     }
 };
 
-/// See background-glass-style
-pub const BackgroundGlassStyle = enum {
-    off,
-    regular,
-    clear,
-};
-
 /// See window-decoration
 pub const WindowDecoration = enum(c_int) {
     auto,