fix alignment bug

sandbox/will/scrollbug.py

@@ -0,0 +1,19 @@
+from textual.app import App, ComposeResult
+from textual.containers import Container
+from textual.widgets import Header, Footer
+
+
+class ScrollApp(App):
+
+    BINDINGS = [("q", "quit", "QUIT")]
+    CSS_PATH = "scrollbug.css"
+
+    def compose(self) -> ComposeResult:
+        yield Header()
+        yield Container(id="test")
+        yield Footer()
+
+
+app = ScrollApp()
+if __name__ == "__main__":
+    app.run()