narrow down rules

docs/examples/introduction/stopwatch.css

@@ -52,3 +52,6 @@ Button {
     visibility: hidden
 }
 
+/* #timers:hover {
+    background: blue;
+} */

docs/examples/introduction/stopwatch.py

@@ -88,6 +88,7 @@ class StopwatchApp(App):
         new_stopwatch = Stopwatch()
         self.query_one("#timers").mount(new_stopwatch)
         new_stopwatch.scroll_visible()
+        self.sub_title = str(len(self.query("Stopwatch")))
 
     def action_remove_stopwatch(self) -> None:
         """Called to remove a timer."""