Further docs updates to get rid of App.dark

docs/blog/posts/release0-38-0.md

@@ -58,7 +58,7 @@ If you do want to style something outside of the widget you can set `SCOPED_CSS=
 ## Light and Dark pseudo selectors
 
 We've also made a slight quality of life improvement to the CSS, by adding `:light` and `:dark` pseudo selectors.
-This allows you to change styles depending on whether you have dark mode enabled or not.
+This allows you to change styles depending on whether the app is currently using a light or dark theme.
 
 This was possible before, just a little verbose.
 Here's how you would do it in 0.37.0:

docs/guide/command_palette.md

@@ -11,8 +11,8 @@ Textual will suggest commands as you type in that input.
 Press ++up++ or ++down++ to select a command from the list, and ++enter++ to invoke it.
 
 Commands are looked up via a *fuzzy* search, which means Textual will show commands that match the keys you type in the same order, but not necessarily at the start of the command.
-For instance the "Toggle light/dark mode" command will be shown if you type "to" (for **to**ggle), but you could also type "dm" (to match **d**ark **m**ode).
-This scheme allows the user to quickly get to a particular command with a minimum of key-presses.
+For instance the "Change theme" command will be shown if you type "ch" (for **ch**ange), but you could also type "th" (to match **t**heme).
+This scheme allows the user to quickly get to a particular command with fewer key-presses.
 
 
 === "Command Palette"

docs/tutorial.md

@@ -117,7 +117,7 @@ If you run this code, you should see something like the following:
 ```{.textual path="docs/examples/tutorial/stopwatch01.py" title="stopwatch01.py"}
 ```
 
-Hit the ++d++ key to toggle between light and dark mode.
+Hit the ++d++ key to toggle between light and dark themes.
 
 ```{.textual path="docs/examples/tutorial/stopwatch01.py" press="d" title="stopwatch01.py"}
 ```

src/textual/app.py

@@ -519,10 +519,10 @@ class MyApp(App[None]):
     """The name of the currently active theme."""
 
     ansi_theme_dark = Reactive(MONOKAI, init=False)
-    """Maps ANSI colors to hex colors using a Rich TerminalTheme object while in dark mode."""
+    """Maps ANSI colors to hex colors using a Rich TerminalTheme object while using a dark theme."""
 
     ansi_theme_light = Reactive(ALABASTER, init=False)
-    """Maps ANSI colors to hex colors using a Rich TerminalTheme object while in light mode."""
+    """Maps ANSI colors to hex colors using a Rich TerminalTheme object while using a light theme."""
 
     ansi_color = Reactive(False)
     """Allow ANSI colors in UI?"""
@@ -4056,6 +4056,15 @@ async def action_toggle_class(self, selector: str, class_name: str) -> None:
         """
         self.screen.query(selector).toggle_class(class_name)
 
+    def action_toggle_dark(self) -> None:
+        """An [action](/guide/actions) to toggle the theme between textual-light
+        and textual-dark. This is offered as a convenience to simplify backwards
+        compatibility with previous versions of Textual which only had light mode
+        and dark mode."""
+        self.theme = (
+            "textual-dark" if self.theme == "textual-light" else "textual-light"
+        )
+
     def action_focus_next(self) -> None:
         """An [action](/guide/actions) to focus the next widget."""
         self.screen.focus_next()

src/textual/widgets/_toggle_button.py

@@ -95,7 +95,7 @@ class ToggleButton(Static, can_focus=True):
 
 
 
-    /* Base button colors (including in dark mode). */
+    /* Base button colors (including in dark themes). */
 
     ToggleButton > .toggle--button {
         text-style: $block-cursor-text-style;
@@ -110,7 +110,7 @@ class ToggleButton(Static, can_focus=True):
         background: $foreground 25%;
     }
 
-    /* Light mode overrides. */
+    /* Light theme overrides. */
     ToggleButton:light {
         color: $text;
         & > .toggle--button {