coindicentally this also fixes #14189

.changeset/great-bulldogs-wonder.md

@@ -0,0 +1,5 @@
+---
+'svelte': patch
+---
+
+fix: prevent nested pseudo class from being marked as unused

packages/svelte/tests/css/samples/not-selector-global/expected.css

@@ -27,3 +27,12 @@
 	span:not(p span) {
 		color: green;
 	}
+
+	.x {
+		.svelte-xyz:not(.foo) {
+			color: green;
+		}
+		&:not(.foo) {
+			color: green;
+		}
+	}

packages/svelte/tests/css/samples/not-selector-global/input.svelte

@@ -34,4 +34,13 @@
 	:global(span:not(p span)) {
 		color: green;
 	}
+
+	:global(.x) {
+		:not(.foo) {
+			color: green;
+		}
+		&:not(.foo) {
+			color: green;
+		}
+	}
 </style>