fix(html): ignore empty selector segments in ScopeVariant

Co-Authored-By: Virgil <virgil@lethean.io>

responsive.go

@@ -82,14 +82,18 @@ func ScopeVariant(name, selector string) string {
 	}
 
 	parts := strings.Split(selector, ",")
+	scoped := make([]string, 0, len(parts))
 	for i := range parts {
-		parts[i] = strings.TrimSpace(parts[i])
-		if parts[i] == "" {
+		part := strings.TrimSpace(parts[i])
+		if part == "" {
 			continue
 		}
-		parts[i] = scope + " " + parts[i]
+		scoped = append(scoped, scope+" "+part)
 	}
-	return strings.Join(parts, ", ")
+	if len(scoped) == 0 {
+		return scope
+	}
+	return strings.Join(scoped, ", ")
 }
 
 // responsive.go: Variant adds a named layout variant (e.g., "desktop", "tablet", "mobile").

responsive_test.go

@@ -200,3 +200,11 @@ func TestScopeVariant_MultipleSelectors(t *testing.T) {
 		t.Fatalf("ScopeVariant with selector list = %q, want %q", got, want)
 	}
 }
+
+func TestScopeVariant_IgnoresEmptySelectorSegments(t *testing.T) {
+	got := ScopeVariant("desktop", ".nav, , .sidebar,")
+	want := `[data-variant="desktop"] .nav, [data-variant="desktop"] .sidebar`
+	if got != want {
+		t.Fatalf("ScopeVariant should skip empty selector segments = %q, want %q", got, want)
+	}
+}