simplify

Author: willmcgugan

src/textual/app.py

@@ -832,11 +832,8 @@ def get_pseudo_classes(self) -> Iterable[str]:
         Returns:
             Names of the pseudo classes.
         """
-        if self.app_focus:
-            yield "focus"
-        else:
-            yield "blur"
-        yield "dark" if self.app.dark else "light"
+        yield "focus" if self.app_focus else "blur"
+        yield "dark" if self.dark else "light"
         if self.is_inline:
             yield "inline"