typing fix

src/textual/_layout.py

@@ -47,6 +47,7 @@ class Layout(ABC):
     ) -> int:
         width: int | None = None
         for child in parent.displayed_children:
+            assert isinstance(child, Widget)
             if not child.is_container:
                 child_width = child.get_content_width(container_size, viewport_size)
                 width = child_width if width is None else max(width, child_width)

src/textual/css/_style_properties.py

@@ -71,7 +71,7 @@ class ScalarProperty:
         self.name = name
 
     def __get__(
-        self, obj: StylesBase, objtype: type[Styles] | None = None
+        self, obj: StylesBase, objtype: type[StylesBase] | None = None
     ) -> Scalar | None:
         """Get the scalar property