Reference doc for text-opacity

docs/examples/styles/text_opacity.css

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+#zero-opacity {
+    text-opacity: 0%;
+}
+
+#quarter-opacity {
+    text-opacity: 25%;
+}
+
+#half-opacity {
+    text-opacity: 50%;
+}
+
+#three-quarter-opacity {
+    text-opacity: 75%;
+}
+
+#full-opacity {
+    text-opacity: 100%;
+}
+
+Static {
+    height: 1fr;
+    text-align: center;
+    text-style: bold;
+}

docs/examples/styles/text_opacity.py

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+from textual.app import App
+from textual.widgets import Static
+
+
+class TextOpacityApp(App):
+    def compose(self):
+        yield Static("text-opacity: 0%", id="zero-opacity")
+        yield Static("text-opacity: 25%", id="quarter-opacity")
+        yield Static("text-opacity: 50%", id="half-opacity")
+        yield Static("text-opacity: 75%", id="three-quarter-opacity")
+        yield Static("text-opacity: 100%", id="full-opacity")
+
+
+app = TextOpacityApp(css_path="text_opacity.css")