Add classes to Tab widget (#2589)

* Add classes to Tab widget

* Update CHANGELOG

CHANGELOG.md

@@ -6,7 +6,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/)
 and this project adheres to [Semantic Versioning](http://semver.org/).
 
 
-## Unrealeased
+## Unreleased
 
 ### Changed
 
@@ -29,6 +29,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 - `Screen.AUTO_FOCUS` now works on the default screen on startup https://github.com/Textualize/textual/pull/2581
 - Fix for setting dark in App `__init__` https://github.com/Textualize/textual/issues/2583
 - Fix issue with scrolling and docks https://github.com/Textualize/textual/issues/2525
+- Fix not being able to use CSS classes with `Tab` https://github.com/Textualize/textual/pull/2589
 
 ### Added
 

src/textual/widgets/_tabs.py

@@ -117,15 +117,17 @@ class Tab(Static):
         label: TextType,
         *,
         id: str | None = None,
+        classes: str | None = None,
     ) -> None:
         """Initialise a Tab.
 
         Args:
             label: The label to use in the tab.
             id: Optional ID for the widget.
+            classes: Space separated list of class names.
         """
         self.label = Text.from_markup(label) if isinstance(label, str) else label
-        super().__init__(id=id)
+        super().__init__(id=id, classes=classes)
         self.update(label)
 
     @property