Reset styles before applying to ensure defaults are restored

examples/basic.css

@@ -2,6 +2,7 @@
 
 App > View {
   docks: side=left/1;
+  text: on #20639b;
 }
 
 Widget:hover {
@@ -28,6 +29,10 @@ Widget:hover {
   border: hkey;
 }
 
+#header.-visible {
+  visibility: hidden;
+}
+
 #content {
   text: white on #20639b;
   border-bottom: hkey #0f2b41;

examples/basic.py

@@ -8,6 +8,7 @@ class BasicApp(App):
     def on_load(self):
         """Bind keys here."""
         self.bind("tab", "toggle_class('#sidebar', '-active')")
+        self.bind("a", "toggle_class('#header', '-visible')")
 
     def on_mount(self):
         """Build layout here."""

src/textual/css/stylesheet.py

@@ -113,8 +113,14 @@ class Stylesheet:
         rule_attributes = defaultdict(list)
 
         _check_rule = self._check_rule
+
+        node.reset_styles()
+
+        # Get the default node CSS rules
         for key, default_specificity, value in node._default_rules:
             rule_attributes[key].append((default_specificity, value))
+
+        # Apply styles on top of the default node CSS rules
         for rule in self.rules:
             for specificity in _check_rule(rule, node):
                 for key, rule_specificity, value in rule.styles.extract_rules(
@@ -123,13 +129,6 @@ class Stylesheet:
                     rule_attributes[key].append((rule_specificity, value))
 
         get_first_item = itemgetter(0)
-
-        log("")
-        log(node)
-        for key, attributes in rule_attributes.items():
-            log(key, key in node.styles.important)
-            log("\t", attributes)
-
         node_rules = [
             (name, max(specificity_rules, key=get_first_item)[1])
             for name, specificity_rules in rule_attributes.items()