message: send_button hovered
diff: @@ -100,7 +100,12 @@ fn new_message_input() -> impl Element {
  }
  fn send_button() -> impl Element {
  + let (hovered, hovered_signal) = Mutable::new_and_signal(false);
  Button::new()
  + .style(Background::new().color_signal(hovered.map(|hovered| {
  + if hovered { NamedColor::Green } else { NamedColor::DarkGreen }
  + })))
  + .on_hovered_change(move |is_hovered| hovered.set(is_hovered))
  .on_press(send_message)
  .label("Send")
  }
  