GTK3,4: Follow Breeze KDecoration border radius

src/gtk3/widgets/_headerbar.scss

@@ -8,7 +8,7 @@
 headerbar {
 	padding: 0px 6px;
 	border-width: 0px 0px 1px 0px;
-	border-radius: 3px 3px 0px 0px;
+	border-radius: 6px 6px 0px 0px;
 	border-style: solid;
 	border-color: gtk("@borders");
 	color: gtk("@theme_titlebar_foreground");

src/gtk3/widgets/_libhandy.scss

@@ -176,3 +176,12 @@ viewswitcherbar {
 		padding: 0;
 	}
 }
+
+window.unified {
+	border-radius: 6px;
+	&.maximized,
+	&.fullscreen,
+	&.tiled {
+		border-radius: 0;
+	}
+}

src/gtk3/widgets/_window_decorations.scss

@@ -8,7 +8,7 @@ decoration {
 	$shadow: rgba(0, 0, 0, 0.5);
 
 	//border: 1px solid transparent;
-	border-radius: $r $r 0 0;
+	border-radius: 6px 6px 0 0;
 	border-width: 0px;
 	box-shadow: 0px 0px 16px $shadow,
 		0px 2px 8px scale-color($shadow, $alpha: -40%);
@@ -30,7 +30,7 @@ decoration {
 		box-shadow: 0 2px 6px 1px rgba(0, 0, 0, 0.1);
 	}
 	.csd & {
-		border-radius: $r;
+		border-radius: 6px;
 		&.popup {
 			box-shadow: 2px 2px 2px 1px rgba(0, 0, 0, 0.1);
 		}

src/gtk4/widgets/_headerbar.scss

@@ -8,7 +8,7 @@
 headerbar {
 	padding: 0px 6px;
 	border-width: 0px 0px 1px 0px;
-	border-radius: 3px 3px 0px 0px;
+	border-radius: 6px 6px 0px 0px;
 	border-style: solid;
 	border-color: gtk("@borders");
 	color: gtk("@theme_titlebar_foreground");

src/gtk4/widgets/_libhandy.scss

@@ -63,3 +63,12 @@ headerbar hdyviewswitcher > button:checked > stack {
 	border-bottom: 3px solid
 		gtk("@theme_button_decoration_focus");
 }
+
+window.unified {
+	border-radius: 6px;
+	&.maximized,
+	&.fullscreen,
+	&.tiled {
+		border-radius: 0;
+	}
+}

src/gtk4/widgets/_window_decorations.scss

@@ -9,7 +9,7 @@ window {
 	$shadow: rgba(0, 0, 0, 0.5);
 
 	//border: 1px solid transparent;
-	border-radius: $r $r 0 0;
+	border-radius: 6px 6px 0 0;
 	border-width: 0px;
 	box-shadow: 0px 0px 16px $shadow,
 		0px 2px 8px scale-color($shadow, $alpha: -40%);
@@ -34,7 +34,7 @@ window {
 		box-shadow: 0 2px 6px 1px rgba(0, 0, 0, 0.1);
 	}
 	.csd & {
-		border-radius: $r;
+		border-radius: 6px;
 		&.popup {
 			box-shadow: 2px 2px 2px 1px rgba(0, 0, 0, 0.1);
 		}