from textual.app import App, ComposeResult from textual.containers import Vertical from textual.widgets import Label class BorderAlphaApp(App[None]): CSS = """ .boxes { height: 3; width: 100%; } #box0 { border: heavy green 0%; } #box1 { border: heavy green 20%; } #box2 { border: heavy green 40%; } #box3 { border: heavy green 60%; } #box4 { border: heavy green 80%; } #box5 { border: heavy green 100%; } """ def compose(self) -> ComposeResult: with Vertical(): for box in range(6): yield Label(id=f"box{box}", classes="boxes") if __name__ == "__main__": BorderAlphaApp().run()